diff --git a/java/src/org/openqa/selenium/chrome/ChromeDriverService.java b/java/src/org/openqa/selenium/chrome/ChromeDriverService.java
index 921ad928ea5fc..fa2bee0167044 100644
--- a/java/src/org/openqa/selenium/chrome/ChromeDriverService.java
+++ b/java/src/org/openqa/selenium/chrome/ChromeDriverService.java
@@ -18,7 +18,6 @@
 package org.openqa.selenium.chrome;
 
 import static java.util.Collections.unmodifiableList;
-import static java.util.Collections.unmodifiableMap;
 import static org.openqa.selenium.remote.Browser.CHROME;
 
 import com.google.auto.service.AutoService;
@@ -27,7 +26,6 @@
 import java.io.OutputStream;
 import java.time.Duration;
 import java.util.ArrayList;
-import java.util.HashMap;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
@@ -110,12 +108,7 @@ public ChromeDriverService(
       @Nullable List<String> args,
       @Nullable Map<String, String> environment)
       throws IOException {
-    super(
-        executable,
-        port,
-        timeout,
-        unmodifiableList(new ArrayList<>(args)),
-        unmodifiableMap(new HashMap<>(environment)));
+    super(executable, port, timeout, args, environment);
   }
 
   public String getDriverName() {
diff --git a/java/src/org/openqa/selenium/edge/EdgeDriverInfo.java b/java/src/org/openqa/selenium/edge/EdgeDriverInfo.java
index 2435c1fae3dbb..23070cee03f44 100644
--- a/java/src/org/openqa/selenium/edge/EdgeDriverInfo.java
+++ b/java/src/org/openqa/selenium/edge/EdgeDriverInfo.java
@@ -21,7 +21,6 @@
 
 import com.google.auto.service.AutoService;
 import java.util.Optional;
-import java.util.logging.Logger;
 import org.openqa.selenium.Capabilities;
 import org.openqa.selenium.ImmutableCapabilities;
 import org.openqa.selenium.SessionNotCreatedException;
@@ -34,8 +33,6 @@
 
 @AutoService(WebDriverInfo.class)
 public class EdgeDriverInfo extends ChromiumDriverInfo {
-  private static final Logger LOG = Logger.getLogger(EdgeDriverInfo.class.getName());
-
   @Override
   public String getDisplayName() {
     return "Edge";
diff --git a/java/src/org/openqa/selenium/edge/EdgeDriverService.java b/java/src/org/openqa/selenium/edge/EdgeDriverService.java
index 6f1ae54147861..2ba4459ebb519 100644
--- a/java/src/org/openqa/selenium/edge/EdgeDriverService.java
+++ b/java/src/org/openqa/selenium/edge/EdgeDriverService.java
@@ -104,7 +104,7 @@ public EdgeDriverService(
       @Nullable List<String> args,
       @Nullable Map<String, String> environment)
       throws IOException {
-    super(executable, port, timeout, List.copyOf(args), Map.copyOf(environment));
+    super(executable, port, timeout, args, environment);
   }
 
   public String getDriverName() {
diff --git a/java/src/org/openqa/selenium/edge/package-info.java b/java/src/org/openqa/selenium/edge/package-info.java
new file mode 100644
index 0000000000000..0ecb0d05d4dd3
--- /dev/null
+++ b/java/src/org/openqa/selenium/edge/package-info.java
@@ -0,0 +1,50 @@
+// Licensed to the Software Freedom Conservancy (SFC) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The SFC licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+/**
+ * Mechanisms to configure and run selenium via the command line. There are two key classes {@link
+ * org.openqa.selenium.cli.CliCommand} and {@link org.openqa.selenium.grid.config.HasRoles}.
+ * Ultimately, these are used to build a {@link org.openqa.selenium.grid.config.Config} instance,
+ * for which there are strongly-typed role-specific classes that use a {@code Config}, such as
+ * {@link org.openqa.selenium.grid.node.docker.DockerOptions}.
+ *
+ * <p>Assuming your {@code CliCommand} extends {@link org.openqa.selenium.grid.TemplateGridCommand},
+ * the process for building the set of flags to use is:
+ *
+ * <ol>
+ *   <li>The default flags are added (these are {@link org.openqa.selenium.grid.server.HelpFlags}
+ *       and {@link org.openqa.selenium.grid.config.ConfigFlags}
+ *   <li>{@link java.util.ServiceLoader} is used to find all implementations of {@link
+ *       org.openqa.selenium.grid.config.HasRoles} where {@link
+ *       org.openqa.selenium.grid.config.HasRoles#getRoles()} is contained within {@link
+ *       org.openqa.selenium.cli.CliCommand#getConfigurableRoles()}.
+ *   <li>Finally all flags returned by {@link
+ *       org.openqa.selenium.grid.TemplateGridCommand#getFlagObjects()} are added.
+ * </ol>
+ *
+ * <p>The flags are then used by JCommander to parse the command arguments. Once that's done, the
+ * raw flags are converted to a {@link org.openqa.selenium.grid.config.Config} by combining all of
+ * the flag objects with system properties and environment variables. This implies that each flag
+ * object has annotated each field with {@link org.openqa.selenium.grid.config.ConfigValue}.
+ *
+ * <p>Ultimately, this means that flag objects have all (most?) fields annotated with JCommander's
+ * {@link com.beust.jcommander.Parameter} annotation as well as {@code ConfigValue}.
+ */
+@NullMarked
+package org.openqa.selenium.edge;
+
+import org.jspecify.annotations.NullMarked;
diff --git a/java/src/org/openqa/selenium/federatedcredentialmanagement/FederatedCredentialManagementAccount.java b/java/src/org/openqa/selenium/federatedcredentialmanagement/FederatedCredentialManagementAccount.java
index ff9248a2eb7f5..d14f0c855ee35 100644
--- a/java/src/org/openqa/selenium/federatedcredentialmanagement/FederatedCredentialManagementAccount.java
+++ b/java/src/org/openqa/selenium/federatedcredentialmanagement/FederatedCredentialManagementAccount.java
@@ -18,7 +18,6 @@
 package org.openqa.selenium.federatedcredentialmanagement;
 
 import java.util.Map;
-import org.jspecify.annotations.NullMarked;
 import org.jspecify.annotations.Nullable;
 
 /**
@@ -29,7 +28,6 @@
  * @see <a href="https://w3c-fedid.github.io/FedCM/#webdriver-accountlist">
  *     https://w3c-fedid.github.io/FedCM/#webdriver-accountlist</a>
  */
-@NullMarked
 public class FederatedCredentialManagementAccount {
   private final @Nullable String accountId;
   private final @Nullable String email;
@@ -57,16 +55,16 @@ public class FederatedCredentialManagementAccount {
   public static final String LOGIN_STATE_SIGNIN = "SignIn";
   public static final String LOGIN_STATE_SIGNUP = "SignUp";
 
-  public FederatedCredentialManagementAccount(Map<String, String> dict) {
-    accountId = (String) dict.getOrDefault("accountId", null);
-    email = (String) dict.getOrDefault("email", null);
-    name = (String) dict.getOrDefault("name", null);
-    givenName = (String) dict.getOrDefault("givenName", null);
-    pictureUrl = (String) dict.getOrDefault("pictureUrl", null);
-    idpConfigUrl = (String) dict.getOrDefault("idpConfigUrl", null);
-    loginState = (String) dict.getOrDefault("loginState", null);
-    termsOfServiceUrl = (String) dict.getOrDefault("termsOfServiceUrl", null);
-    privacyPolicyUrl = (String) dict.getOrDefault("privacyPolicyUrl", null);
+  public FederatedCredentialManagementAccount(Map<String, @Nullable String> dict) {
+    accountId = dict.getOrDefault("accountId", null);
+    email = dict.getOrDefault("email", null);
+    name = dict.getOrDefault("name", null);
+    givenName = dict.getOrDefault("givenName", null);
+    pictureUrl = dict.getOrDefault("pictureUrl", null);
+    idpConfigUrl = dict.getOrDefault("idpConfigUrl", null);
+    loginState = dict.getOrDefault("loginState", null);
+    termsOfServiceUrl = dict.getOrDefault("termsOfServiceUrl", null);
+    privacyPolicyUrl = dict.getOrDefault("privacyPolicyUrl", null);
   }
 
   public @Nullable String getAccountid() {
diff --git a/java/src/org/openqa/selenium/federatedcredentialmanagement/FederatedCredentialManagementDialog.java b/java/src/org/openqa/selenium/federatedcredentialmanagement/FederatedCredentialManagementDialog.java
index 3c12d92e0c6c0..4882141cc0177 100644
--- a/java/src/org/openqa/selenium/federatedcredentialmanagement/FederatedCredentialManagementDialog.java
+++ b/java/src/org/openqa/selenium/federatedcredentialmanagement/FederatedCredentialManagementDialog.java
@@ -18,7 +18,6 @@
 package org.openqa.selenium.federatedcredentialmanagement;
 
 import java.util.List;
-import org.jspecify.annotations.NullMarked;
 import org.jspecify.annotations.Nullable;
 
 /**
@@ -26,7 +25,6 @@
  *
  * @see <a href="https://w3c-fedid.github.io/FedCM/">https://w3c-fedid.github.io/FedCM/</a>
  */
-@NullMarked
 public interface FederatedCredentialManagementDialog {
 
   String DIALOG_TYPE_ACCOUNT_LIST = "AccountChooser";
diff --git a/java/src/org/openqa/selenium/federatedcredentialmanagement/HasFederatedCredentialManagement.java b/java/src/org/openqa/selenium/federatedcredentialmanagement/HasFederatedCredentialManagement.java
index 501a52d6e05e7..2026f66617758 100644
--- a/java/src/org/openqa/selenium/federatedcredentialmanagement/HasFederatedCredentialManagement.java
+++ b/java/src/org/openqa/selenium/federatedcredentialmanagement/HasFederatedCredentialManagement.java
@@ -17,13 +17,11 @@
 
 package org.openqa.selenium.federatedcredentialmanagement;
 
-import org.jspecify.annotations.NullMarked;
 import org.jspecify.annotations.Nullable;
 import org.openqa.selenium.Beta;
 
 /** Used by classes to indicate that they can interact with FedCM dialogs. */
 @Beta
-@NullMarked
 public interface HasFederatedCredentialManagement {
   /**
    * Disables the promise rejection delay.
diff --git a/java/src/org/openqa/selenium/federatedcredentialmanagement/package-info.java b/java/src/org/openqa/selenium/federatedcredentialmanagement/package-info.java
new file mode 100644
index 0000000000000..359e361a886f5
--- /dev/null
+++ b/java/src/org/openqa/selenium/federatedcredentialmanagement/package-info.java
@@ -0,0 +1,50 @@
+// Licensed to the Software Freedom Conservancy (SFC) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The SFC licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+/**
+ * Mechanisms to configure and run selenium via the command line. There are two key classes {@link
+ * org.openqa.selenium.cli.CliCommand} and {@link org.openqa.selenium.grid.config.HasRoles}.
+ * Ultimately, these are used to build a {@link org.openqa.selenium.grid.config.Config} instance,
+ * for which there are strongly-typed role-specific classes that use a {@code Config}, such as
+ * {@link org.openqa.selenium.grid.node.docker.DockerOptions}.
+ *
+ * <p>Assuming your {@code CliCommand} extends {@link org.openqa.selenium.grid.TemplateGridCommand},
+ * the process for building the set of flags to use is:
+ *
+ * <ol>
+ *   <li>The default flags are added (these are {@link org.openqa.selenium.grid.server.HelpFlags}
+ *       and {@link org.openqa.selenium.grid.config.ConfigFlags}
+ *   <li>{@link java.util.ServiceLoader} is used to find all implementations of {@link
+ *       org.openqa.selenium.grid.config.HasRoles} where {@link
+ *       org.openqa.selenium.grid.config.HasRoles#getRoles()} is contained within {@link
+ *       org.openqa.selenium.cli.CliCommand#getConfigurableRoles()}.
+ *   <li>Finally all flags returned by {@link
+ *       org.openqa.selenium.grid.TemplateGridCommand#getFlagObjects()} are added.
+ * </ol>
+ *
+ * <p>The flags are then used by JCommander to parse the command arguments. Once that's done, the
+ * raw flags are converted to a {@link org.openqa.selenium.grid.config.Config} by combining all of
+ * the flag objects with system properties and environment variables. This implies that each flag
+ * object has annotated each field with {@link org.openqa.selenium.grid.config.ConfigValue}.
+ *
+ * <p>Ultimately, this means that flag objects have all (most?) fields annotated with JCommander's
+ * {@link com.beust.jcommander.Parameter} annotation as well as {@code ConfigValue}.
+ */
+@NullMarked
+package org.openqa.selenium.federatedcredentialmanagement;
+
+import org.jspecify.annotations.NullMarked;
diff --git a/java/src/org/openqa/selenium/firefox/AddHasContext.java b/java/src/org/openqa/selenium/firefox/AddHasContext.java
index 787892239fc20..4369ab6cda1d2 100644
--- a/java/src/org/openqa/selenium/firefox/AddHasContext.java
+++ b/java/src/org/openqa/selenium/firefox/AddHasContext.java
@@ -69,8 +69,7 @@ public void setContext(FirefoxCommandContext context) {
 
       @Override
       public FirefoxCommandContext getContext() {
-        String context = (String) executeMethod.execute(GET_CONTEXT, null);
-
+        String context = executeMethod.executeRequired(GET_CONTEXT, null);
         return FirefoxCommandContext.fromString(context);
       }
     };
diff --git a/java/src/org/openqa/selenium/firefox/AddHasExtensions.java b/java/src/org/openqa/selenium/firefox/AddHasExtensions.java
index d1b21880bbdb6..671199bd2e494 100644
--- a/java/src/org/openqa/selenium/firefox/AddHasExtensions.java
+++ b/java/src/org/openqa/selenium/firefox/AddHasExtensions.java
@@ -95,9 +95,8 @@ public String installExtension(Path path, Boolean temporary) {
           throw new InvalidArgumentException(path + " is an invalid path", e);
         }
 
-        return (String)
-            executeMethod.execute(
-                INSTALL_EXTENSION, Map.of("addon", encoded, "temporary", temporary));
+        return executeMethod.executeRequired(
+            INSTALL_EXTENSION, Map.of("addon", encoded, "temporary", temporary));
       }
 
       private byte[] zipDirectory(Path path) throws IOException {
@@ -105,7 +104,7 @@ private byte[] zipDirectory(Path path) throws IOException {
         try (ZipOutputStream zos = new ZipOutputStream(baos)) {
           Files.walkFileTree(
               path,
-              new SimpleFileVisitor<Path>() {
+              new SimpleFileVisitor<>() {
                 @Override
                 public FileVisitResult visitFile(Path file, BasicFileAttributes attrs)
                     throws IOException {
diff --git a/java/src/org/openqa/selenium/firefox/FileExtension.java b/java/src/org/openqa/selenium/firefox/FileExtension.java
index 7f7253c22df85..db9e755f00527 100644
--- a/java/src/org/openqa/selenium/firefox/FileExtension.java
+++ b/java/src/org/openqa/selenium/firefox/FileExtension.java
@@ -18,6 +18,7 @@
 package org.openqa.selenium.firefox;
 
 import static java.nio.charset.StandardCharsets.UTF_8;
+import static java.util.Objects.requireNonNull;
 import static org.openqa.selenium.json.Json.MAP_TYPE;
 
 import java.io.BufferedInputStream;
@@ -131,7 +132,7 @@ private String readIdFromManifestJson(File root) {
         JsonInput json = new Json().newInput(reader)) {
       String addOnId = null;
 
-      Map<String, Object> manifestObject = json.read(MAP_TYPE);
+      Map<String, Object> manifestObject = json.readNonNull(MAP_TYPE);
       if (manifestObject.get("applications") instanceof Map) {
         Map<?, ?> applicationObj = (Map<?, ?>) manifestObject.get("applications");
         if (applicationObj.get("gecko") instanceof Map) {
@@ -143,10 +144,14 @@ private String readIdFromManifestJson(File root) {
       }
 
       if (addOnId == null || addOnId.isEmpty()) {
-        addOnId =
-            ((String) manifestObject.get("name")).replaceAll(" ", "")
-                + "@"
-                + manifestObject.get("version");
+        String name =
+            (String)
+                requireNonNull(
+                    manifestObject.get("name"),
+                    () ->
+                        "Manifest should contain either 'applications' or 'name', but received: "
+                            + manifestObject);
+        addOnId = name.replaceAll(" ", "") + "@" + manifestObject.get("version");
       }
 
       return addOnId;
@@ -158,9 +163,8 @@ private String readIdFromManifestJson(File root) {
   }
 
   private String readIdFromInstallRdf(File root) {
+    File installRdf = new File(root, "install.rdf");
     try {
-      File installRdf = new File(root, "install.rdf");
-
       DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
       factory.setFeature("http://apache.org/xml/features/disallow-doctype-decl", true);
       factory.setNamespaceAware(true);
@@ -214,7 +218,7 @@ public Iterator<String> getPrefixes(String uri) {
       }
       return id;
     } catch (Exception e) {
-      throw new WebDriverException(e);
+      throw new WebDriverException("Failed to read id from " + installRdf.getAbsolutePath(), e);
     }
   }
 }
diff --git a/java/src/org/openqa/selenium/firefox/FirefoxCommandContext.java b/java/src/org/openqa/selenium/firefox/FirefoxCommandContext.java
index 7c683788938a7..07e5208d0c978 100644
--- a/java/src/org/openqa/selenium/firefox/FirefoxCommandContext.java
+++ b/java/src/org/openqa/selenium/firefox/FirefoxCommandContext.java
@@ -32,17 +32,15 @@ public enum FirefoxCommandContext {
 
   @Override
   public String toString() {
-    return String.valueOf(text);
+    return text;
   }
 
   public static FirefoxCommandContext fromString(String text) {
-    if (text != null) {
-      for (FirefoxCommandContext b : FirefoxCommandContext.values()) {
-        if (text.equalsIgnoreCase(b.text)) {
-          return b;
-        }
+    for (FirefoxCommandContext b : FirefoxCommandContext.values()) {
+      if (text.equalsIgnoreCase(b.text)) {
+        return b;
       }
     }
-    return null;
+    throw new IllegalArgumentException("Unknown Firefox context: " + text);
   }
 }
diff --git a/java/src/org/openqa/selenium/firefox/FirefoxDriver.java b/java/src/org/openqa/selenium/firefox/FirefoxDriver.java
index a84f836f374b8..2546a8556e971 100644
--- a/java/src/org/openqa/selenium/firefox/FirefoxDriver.java
+++ b/java/src/org/openqa/selenium/firefox/FirefoxDriver.java
@@ -27,7 +27,6 @@
 import java.util.logging.Logger;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
-import org.jspecify.annotations.NonNull;
 import org.openqa.selenium.Beta;
 import org.openqa.selenium.Capabilities;
 import org.openqa.selenium.ImmutableCapabilities;
@@ -169,6 +168,8 @@ public static RemoteWebDriverBuilder builder() {
 
   /** Check capabilities and proxy if it is set */
   private static Capabilities checkCapabilitiesAndProxy(Capabilities capabilities) {
+    // TODO I think we can remove this null check
+    //noinspection ConstantValue
     if (capabilities == null) {
       return new ImmutableCapabilities();
     }
@@ -184,7 +185,6 @@ private static Capabilities checkCapabilitiesAndProxy(Capabilities capabilities)
     return caps;
   }
 
-  @NonNull
   @Override
   public Capabilities getCapabilities() {
     return capabilities;
diff --git a/java/src/org/openqa/selenium/firefox/FirefoxDriverLogLevel.java b/java/src/org/openqa/selenium/firefox/FirefoxDriverLogLevel.java
index b46e762214b84..e7366fc74f9d2 100644
--- a/java/src/org/openqa/selenium/firefox/FirefoxDriverLogLevel.java
+++ b/java/src/org/openqa/selenium/firefox/FirefoxDriverLogLevel.java
@@ -21,6 +21,7 @@
 import java.util.Locale;
 import java.util.Map;
 import java.util.logging.Level;
+import org.jspecify.annotations.Nullable;
 
 /**
  * <a href="https://github.com/mozilla/geckodriver#log-object">Log levels</a> defined by GeckoDriver
@@ -51,7 +52,8 @@ public String toString() {
     return super.toString().toLowerCase(Locale.ENGLISH);
   }
 
-  public static FirefoxDriverLogLevel fromString(String text) {
+  @Nullable
+  public static FirefoxDriverLogLevel fromString(@Nullable String text) {
     if (text != null) {
       for (FirefoxDriverLogLevel b : FirefoxDriverLogLevel.values()) {
         if (text.equalsIgnoreCase(b.toString())) {
@@ -70,6 +72,7 @@ Map<String, String> toJson() {
     return Collections.singletonMap("level", toString());
   }
 
+  @Nullable
   static FirefoxDriverLogLevel fromJson(Map<String, String> json) {
     return fromString(json.get("level"));
   }
diff --git a/java/src/org/openqa/selenium/firefox/FirefoxDriverService.java b/java/src/org/openqa/selenium/firefox/FirefoxDriverService.java
index 65e9ed83be01d..69f7626fe8244 100644
--- a/java/src/org/openqa/selenium/firefox/FirefoxDriverService.java
+++ b/java/src/org/openqa/selenium/firefox/FirefoxDriverService.java
@@ -35,7 +35,7 @@ public abstract class FirefoxDriverService extends DriverService {
    * @param environment The environment for the launched server.
    * @throws IOException If an I/O error occurs.
    */
-  public FirefoxDriverService(
+  protected FirefoxDriverService(
       @Nullable File executable,
       int port,
       @Nullable Duration timeout,
diff --git a/java/src/org/openqa/selenium/firefox/FirefoxOptions.java b/java/src/org/openqa/selenium/firefox/FirefoxOptions.java
index 6950661874cc6..641d6253fd34a 100644
--- a/java/src/org/openqa/selenium/firefox/FirefoxOptions.java
+++ b/java/src/org/openqa/selenium/firefox/FirefoxOptions.java
@@ -227,11 +227,11 @@ public FirefoxOptions addPreference(String key, Object value) {
     return setFirefoxOption(Keys.PREFS, Collections.unmodifiableMap(newPrefs));
   }
 
-  Map<String, Object> prefs() {
+  @Nullable Map<String, Object> prefs() {
     return getOption(Keys.PREFS);
   }
 
-  String profile() {
+  @Nullable String profile() {
     return getOption(Keys.PROFILE);
   }
 
@@ -293,6 +293,7 @@ protected Set<String> getExtraCapabilityNames() {
     return Collections.unmodifiableSet(names);
   }
 
+  @Nullable
   @Override
   protected Object getExtraCapability(String capabilityName) {
     Require.nonNull("Capability name", capabilityName);
@@ -440,6 +441,7 @@ private enum Keys {
       @Override
       public void amend(Map<String, Object> sourceOptions, Map<String, Object> toAmend) {}
 
+      @Nullable
       @Override
       public Object mirror(Map<String, Object> first, Map<String, Object> second) {
         return null;
@@ -465,6 +467,7 @@ public void amend(Map<String, Object> sourceOptions, Map<String, Object> toAmend
         toAmend.put(key(), Collections.unmodifiableList(new ArrayList<>(newArgs)));
       }
 
+      @Nullable
       @Override
       public Object mirror(Map<String, Object> first, Map<String, Object> second) {
         Object rawFirst = first.getOrDefault(key(), new ArrayList<>());
@@ -494,6 +497,7 @@ public void amend(Map<String, Object> sourceOptions, Map<String, Object> toAmend
         }
       }
 
+      @Nullable
       @Override
       public Object mirror(Map<String, Object> first, Map<String, Object> second) {
         Object value = second.get(key());
@@ -527,6 +531,7 @@ public void amend(Map<String, Object> sourceOptions, Map<String, Object> toAmend
         toAmend.put(key(), Collections.unmodifiableMap(collected));
       }
 
+      @Nullable
       @Override
       public Object mirror(Map<String, Object> first, Map<String, Object> second) {
         Object rawFirst = first.getOrDefault(key(), new TreeMap<>());
@@ -559,6 +564,7 @@ public void amend(Map<String, Object> sourceOptions, Map<String, Object> toAmend
         toAmend.put(key(), o);
       }
 
+      @Nullable
       @Override
       public Object mirror(Map<String, Object> first, Map<String, Object> second) {
         Object value = second.get(key());
@@ -590,6 +596,7 @@ public void amend(Map<String, Object> sourceOptions, Map<String, Object> toAmend
         toAmend.put(key(), Collections.unmodifiableMap(collected));
       }
 
+      @Nullable
       @Override
       public Object mirror(Map<String, Object> first, Map<String, Object> second) {
         Object rawFirst = first.getOrDefault(key(), new TreeMap<>());
@@ -627,6 +634,7 @@ public void amend(Map<String, Object> sourceOptions, Map<String, Object> toAmend
         toAmend.put(key(), o);
       }
 
+      @Nullable
       @Override
       public Object mirror(Map<String, Object> first, Map<String, Object> second) {
         Object value = second.get(key());
@@ -657,6 +665,7 @@ public String key() {
 
     public abstract void amend(Map<String, Object> sourceOptions, Map<String, Object> toAmend);
 
+    @Nullable
     public abstract Object mirror(Map<String, Object> first, Map<String, Object> second);
   }
 }
diff --git a/java/src/org/openqa/selenium/firefox/FirefoxProfile.java b/java/src/org/openqa/selenium/firefox/FirefoxProfile.java
index f39b5e1fa33c9..023bf8571cf40 100644
--- a/java/src/org/openqa/selenium/firefox/FirefoxProfile.java
+++ b/java/src/org/openqa/selenium/firefox/FirefoxProfile.java
@@ -26,6 +26,7 @@
 import java.nio.charset.Charset;
 import java.util.HashMap;
 import java.util.Map;
+import org.jspecify.annotations.Nullable;
 import org.openqa.selenium.WebDriverException;
 import org.openqa.selenium.io.FileHandler;
 import org.openqa.selenium.io.TemporaryFilesystem;
@@ -38,7 +39,7 @@ public class FirefoxProfile {
   private static final String ASSUME_UNTRUSTED_ISSUER_PREF = "webdriver_assume_untrusted_issuer";
   private final Preferences additionalPrefs;
   private final Map<String, Extension> extensions = new HashMap<>();
-  private final File model;
+  private @Nullable final File model;
   private boolean loadNoFocusLib;
   private boolean acceptUntrustedCerts;
   private boolean untrustedCertIssuer;
@@ -54,7 +55,7 @@ public FirefoxProfile() {
    *
    * @param profileDir The profile directory to use as a model.
    */
-  public FirefoxProfile(File profileDir) {
+  public FirefoxProfile(@Nullable File profileDir) {
     additionalPrefs = new Preferences();
     model = profileDir;
     verifyModel(model);
@@ -124,7 +125,7 @@ public boolean getBooleanPreference(String key, boolean defaultValue) {
     return defaultValue;
   }
 
-  private void verifyModel(File model) {
+  private void verifyModel(@Nullable File model) {
     if (model == null) {
       return;
     }
@@ -292,8 +293,10 @@ public FirefoxProfile setAssumeUntrustedCertificateIssuer(boolean untrustedIssue
     return this;
   }
 
-  public void clean(File profileDir) {
-    TemporaryFilesystem.getDefaultTmpFS().deleteTempDir(profileDir);
+  public void clean(@Nullable File profileDir) {
+    if (profileDir != null) {
+      TemporaryFilesystem.getDefaultTmpFS().deleteTempDir(profileDir);
+    }
   }
 
   String toJson() throws IOException {
@@ -336,7 +339,7 @@ public File layoutOnDisk() {
     }
   }
 
-  protected void copyModel(File sourceDir, File profileDir) throws IOException {
+  protected void copyModel(@Nullable File sourceDir, File profileDir) throws IOException {
     if (sourceDir == null || !sourceDir.exists()) {
       return;
     }
diff --git a/java/src/org/openqa/selenium/firefox/GeckoDriverInfo.java b/java/src/org/openqa/selenium/firefox/GeckoDriverInfo.java
index dfb371978a18b..da4503b97ea01 100644
--- a/java/src/org/openqa/selenium/firefox/GeckoDriverInfo.java
+++ b/java/src/org/openqa/selenium/firefox/GeckoDriverInfo.java
@@ -22,7 +22,6 @@
 
 import com.google.auto.service.AutoService;
 import java.util.Optional;
-import java.util.logging.Logger;
 import org.openqa.selenium.Capabilities;
 import org.openqa.selenium.ImmutableCapabilities;
 import org.openqa.selenium.SessionNotCreatedException;
@@ -33,8 +32,6 @@
 
 @AutoService(WebDriverInfo.class)
 public class GeckoDriverInfo implements WebDriverInfo {
-  private static final Logger LOG = Logger.getLogger(GeckoDriverInfo.class.getName());
-
   @Override
   public String getDisplayName() {
     return "Firefox";
diff --git a/java/src/org/openqa/selenium/firefox/Preferences.java b/java/src/org/openqa/selenium/firefox/Preferences.java
index 51f272b323962..59b182573804e 100644
--- a/java/src/org/openqa/selenium/firefox/Preferences.java
+++ b/java/src/org/openqa/selenium/firefox/Preferences.java
@@ -32,6 +32,7 @@
 import java.util.Map;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
+import org.jspecify.annotations.Nullable;
 import org.openqa.selenium.WebDriverException;
 import org.openqa.selenium.json.Json;
 
@@ -183,7 +184,7 @@ private Object preferenceAsValue(String toConvert) {
     }
   }
 
-  Object getPreference(String key) {
+  @Nullable Object getPreference(String key) {
     return allPrefs.get(key);
   }
 
diff --git a/java/src/org/openqa/selenium/firefox/ProfilesIni.java b/java/src/org/openqa/selenium/firefox/ProfilesIni.java
index 8e22caa5107e1..535e12921ea20 100644
--- a/java/src/org/openqa/selenium/firefox/ProfilesIni.java
+++ b/java/src/org/openqa/selenium/firefox/ProfilesIni.java
@@ -28,6 +28,7 @@
 import java.text.MessageFormat;
 import java.util.HashMap;
 import java.util.Map;
+import org.jspecify.annotations.Nullable;
 import org.openqa.selenium.Platform;
 import org.openqa.selenium.WebDriverException;
 import org.openqa.selenium.io.FileHandler;
@@ -41,7 +42,7 @@ public ProfilesIni() {
     profiles = readProfiles(appData);
   }
 
-  protected Map<String, File> readProfiles(File appData) {
+  protected Map<String, File> readProfiles(@Nullable File appData) {
     Map<String, File> toReturn = new HashMap<>();
 
     File profilesIni = new File(appData, "profiles.ini");
@@ -95,13 +96,16 @@ protected Map<String, File> readProfiles(File appData) {
     return toReturn;
   }
 
-  protected File newProfile(String name, File appData, String path, boolean isRelative) {
+  @Nullable
+  protected File newProfile(
+      @Nullable String name, @Nullable File appData, @Nullable String path, boolean isRelative) {
     if (name != null && path != null) {
       return isRelative ? new File(appData, path) : new File(path);
     }
     return null;
   }
 
+  @Nullable
   public FirefoxProfile getProfile(String profileName) {
     File profileDir = profiles.get(profileName);
     if (profileDir == null) {
@@ -127,6 +131,7 @@ public FirefoxProfile getProfile(String profileName) {
     return new FirefoxProfile(tempDir);
   }
 
+  @Nullable
   protected File locateAppDataDirectory(Platform os) {
     File appData;
     if (os.is(WINDOWS)) {
diff --git a/java/src/org/openqa/selenium/firefox/package-info.java b/java/src/org/openqa/selenium/firefox/package-info.java
new file mode 100644
index 0000000000000..45dd7c8f0a7dc
--- /dev/null
+++ b/java/src/org/openqa/selenium/firefox/package-info.java
@@ -0,0 +1,21 @@
+// Licensed to the Software Freedom Conservancy (SFC) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The SFC licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+@NullMarked
+package org.openqa.selenium.firefox;
+
+import org.jspecify.annotations.NullMarked;
diff --git a/java/src/org/openqa/selenium/ie/ElementScrollBehavior.java b/java/src/org/openqa/selenium/ie/ElementScrollBehavior.java
index c816170757213..c97cc1de12d20 100644
--- a/java/src/org/openqa/selenium/ie/ElementScrollBehavior.java
+++ b/java/src/org/openqa/selenium/ie/ElementScrollBehavior.java
@@ -17,6 +17,8 @@
 
 package org.openqa.selenium.ie;
 
+import org.jspecify.annotations.Nullable;
+
 public enum ElementScrollBehavior {
   TOP(0),
   BOTTOM(1),
@@ -33,6 +35,7 @@ public String toString() {
     return String.valueOf(value);
   }
 
+  @Nullable
   public static ElementScrollBehavior fromString(String text) {
     for (ElementScrollBehavior b : ElementScrollBehavior.values()) {
       if (text.equalsIgnoreCase(b.toString())) {
diff --git a/java/src/org/openqa/selenium/ie/InternetExplorerDriverInfo.java b/java/src/org/openqa/selenium/ie/InternetExplorerDriverInfo.java
index 4ac3ae75f856e..7713ba8ff91ff 100644
--- a/java/src/org/openqa/selenium/ie/InternetExplorerDriverInfo.java
+++ b/java/src/org/openqa/selenium/ie/InternetExplorerDriverInfo.java
@@ -22,7 +22,6 @@
 
 import com.google.auto.service.AutoService;
 import java.util.Optional;
-import java.util.logging.Logger;
 import org.openqa.selenium.Capabilities;
 import org.openqa.selenium.ImmutableCapabilities;
 import org.openqa.selenium.Platform;
@@ -34,8 +33,6 @@
 
 @AutoService(WebDriverInfo.class)
 public class InternetExplorerDriverInfo implements WebDriverInfo {
-  private static final Logger LOG = Logger.getLogger(InternetExplorerDriverInfo.class.getName());
-
   @Override
   public String getDisplayName() {
     return "Internet Explorer";
diff --git a/java/src/org/openqa/selenium/ie/InternetExplorerDriverService.java b/java/src/org/openqa/selenium/ie/InternetExplorerDriverService.java
index 3cb43892c6e85..f02cfa5dd43aa 100644
--- a/java/src/org/openqa/selenium/ie/InternetExplorerDriverService.java
+++ b/java/src/org/openqa/selenium/ie/InternetExplorerDriverService.java
@@ -18,7 +18,6 @@
 package org.openqa.selenium.ie;
 
 import static java.util.Collections.unmodifiableList;
-import static java.util.Collections.unmodifiableMap;
 import static org.openqa.selenium.remote.Browser.IE;
 
 import com.google.auto.service.AutoService;
@@ -26,7 +25,6 @@
 import java.io.IOException;
 import java.time.Duration;
 import java.util.ArrayList;
-import java.util.HashMap;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
@@ -85,12 +83,7 @@ public InternetExplorerDriverService(
       @Nullable List<String> args,
       @Nullable Map<String, String> environment)
       throws IOException {
-    super(
-        executable,
-        port,
-        timeout,
-        unmodifiableList(new ArrayList<>(args)),
-        unmodifiableMap(new HashMap<>(environment)));
+    super(executable, port, timeout, args, environment);
   }
 
   public String getDriverName() {
diff --git a/java/src/org/openqa/selenium/ie/InternetExplorerOptions.java b/java/src/org/openqa/selenium/ie/InternetExplorerOptions.java
index 84ceef9965d60..6f1c5ccc1c381 100644
--- a/java/src/org/openqa/selenium/ie/InternetExplorerOptions.java
+++ b/java/src/org/openqa/selenium/ie/InternetExplorerOptions.java
@@ -42,6 +42,7 @@
 import java.util.concurrent.TimeUnit;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
+import org.jspecify.annotations.Nullable;
 import org.openqa.selenium.Capabilities;
 import org.openqa.selenium.internal.Require;
 import org.openqa.selenium.remote.AbstractDriverOptions;
@@ -276,6 +277,7 @@ protected Set<String> getExtraCapabilityNames() {
     return Collections.emptySet();
   }
 
+  @Nullable
   @Override
   protected Object getExtraCapability(String capabilityName) {
     Require.nonNull("Capability name", capabilityName);
diff --git a/java/src/org/openqa/selenium/ie/package-info.java b/java/src/org/openqa/selenium/ie/package-info.java
new file mode 100644
index 0000000000000..e2d33d56dc710
--- /dev/null
+++ b/java/src/org/openqa/selenium/ie/package-info.java
@@ -0,0 +1,50 @@
+// Licensed to the Software Freedom Conservancy (SFC) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The SFC licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+/**
+ * Mechanisms to configure and run selenium via the command line. There are two key classes {@link
+ * org.openqa.selenium.cli.CliCommand} and {@link org.openqa.selenium.grid.config.HasRoles}.
+ * Ultimately, these are used to build a {@link org.openqa.selenium.grid.config.Config} instance,
+ * for which there are strongly-typed role-specific classes that use a {@code Config}, such as
+ * {@link org.openqa.selenium.grid.node.docker.DockerOptions}.
+ *
+ * <p>Assuming your {@code CliCommand} extends {@link org.openqa.selenium.grid.TemplateGridCommand},
+ * the process for building the set of flags to use is:
+ *
+ * <ol>
+ *   <li>The default flags are added (these are {@link org.openqa.selenium.grid.server.HelpFlags}
+ *       and {@link org.openqa.selenium.grid.config.ConfigFlags}
+ *   <li>{@link java.util.ServiceLoader} is used to find all implementations of {@link
+ *       org.openqa.selenium.grid.config.HasRoles} where {@link
+ *       org.openqa.selenium.grid.config.HasRoles#getRoles()} is contained within {@link
+ *       org.openqa.selenium.cli.CliCommand#getConfigurableRoles()}.
+ *   <li>Finally all flags returned by {@link
+ *       org.openqa.selenium.grid.TemplateGridCommand#getFlagObjects()} are added.
+ * </ol>
+ *
+ * <p>The flags are then used by JCommander to parse the command arguments. Once that's done, the
+ * raw flags are converted to a {@link org.openqa.selenium.grid.config.Config} by combining all of
+ * the flag objects with system properties and environment variables. This implies that each flag
+ * object has annotated each field with {@link org.openqa.selenium.grid.config.ConfigValue}.
+ *
+ * <p>Ultimately, this means that flag objects have all (most?) fields annotated with JCommander's
+ * {@link com.beust.jcommander.Parameter} annotation as well as {@code ConfigValue}.
+ */
+@NullMarked
+package org.openqa.selenium.ie;
+
+import org.jspecify.annotations.NullMarked;
diff --git a/java/src/org/openqa/selenium/print/PageMargin.java b/java/src/org/openqa/selenium/print/PageMargin.java
index 6fe27e6063e5a..6c18bf3588a7d 100644
--- a/java/src/org/openqa/selenium/print/PageMargin.java
+++ b/java/src/org/openqa/selenium/print/PageMargin.java
@@ -18,9 +18,7 @@
 package org.openqa.selenium.print;
 
 import java.util.Map;
-import org.jspecify.annotations.NullMarked;
 
-@NullMarked
 public class PageMargin {
   private final double top;
   private final double bottom;
diff --git a/java/src/org/openqa/selenium/print/PageSize.java b/java/src/org/openqa/selenium/print/PageSize.java
index a673fda24ec45..ff8f3ab2489b1 100644
--- a/java/src/org/openqa/selenium/print/PageSize.java
+++ b/java/src/org/openqa/selenium/print/PageSize.java
@@ -19,9 +19,8 @@
 
 import java.util.HashMap;
 import java.util.Map;
-import org.jspecify.annotations.NullMarked;
+import org.openqa.selenium.internal.Require;
 
-@NullMarked
 public class PageSize {
   private final double height;
   private final double width;
@@ -52,9 +51,7 @@ public double getWidth() {
   }
 
   public static PageSize setPageSize(PageSize pageSize) {
-    if (pageSize == null) {
-      throw new IllegalArgumentException("Page size cannot be null");
-    }
+    Require.nonNull("Page size", pageSize);
     return new PageSize(pageSize.getHeight(), pageSize.getWidth());
   }
 
diff --git a/java/src/org/openqa/selenium/print/PrintOptions.java b/java/src/org/openqa/selenium/print/PrintOptions.java
index 1e1b7a86da3d5..019e051979f89 100644
--- a/java/src/org/openqa/selenium/print/PrintOptions.java
+++ b/java/src/org/openqa/selenium/print/PrintOptions.java
@@ -20,11 +20,9 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import org.jspecify.annotations.NullMarked;
 import org.jspecify.annotations.Nullable;
 import org.openqa.selenium.internal.Require;
 
-@NullMarked
 public class PrintOptions {
 
   public enum Orientation {
diff --git a/java/src/org/openqa/selenium/print/package-info.java b/java/src/org/openqa/selenium/print/package-info.java
new file mode 100644
index 0000000000000..48ef4b6fe9f52
--- /dev/null
+++ b/java/src/org/openqa/selenium/print/package-info.java
@@ -0,0 +1,50 @@
+// Licensed to the Software Freedom Conservancy (SFC) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The SFC licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+/**
+ * Mechanisms to configure and run selenium via the command line. There are two key classes {@link
+ * org.openqa.selenium.cli.CliCommand} and {@link org.openqa.selenium.grid.config.HasRoles}.
+ * Ultimately, these are used to build a {@link org.openqa.selenium.grid.config.Config} instance,
+ * for which there are strongly-typed role-specific classes that use a {@code Config}, such as
+ * {@link org.openqa.selenium.grid.node.docker.DockerOptions}.
+ *
+ * <p>Assuming your {@code CliCommand} extends {@link org.openqa.selenium.grid.TemplateGridCommand},
+ * the process for building the set of flags to use is:
+ *
+ * <ol>
+ *   <li>The default flags are added (these are {@link org.openqa.selenium.grid.server.HelpFlags}
+ *       and {@link org.openqa.selenium.grid.config.ConfigFlags}
+ *   <li>{@link java.util.ServiceLoader} is used to find all implementations of {@link
+ *       org.openqa.selenium.grid.config.HasRoles} where {@link
+ *       org.openqa.selenium.grid.config.HasRoles#getRoles()} is contained within {@link
+ *       org.openqa.selenium.cli.CliCommand#getConfigurableRoles()}.
+ *   <li>Finally all flags returned by {@link
+ *       org.openqa.selenium.grid.TemplateGridCommand#getFlagObjects()} are added.
+ * </ol>
+ *
+ * <p>The flags are then used by JCommander to parse the command arguments. Once that's done, the
+ * raw flags are converted to a {@link org.openqa.selenium.grid.config.Config} by combining all of
+ * the flag objects with system properties and environment variables. This implies that each flag
+ * object has annotated each field with {@link org.openqa.selenium.grid.config.ConfigValue}.
+ *
+ * <p>Ultimately, this means that flag objects have all (most?) fields annotated with JCommander's
+ * {@link com.beust.jcommander.Parameter} annotation as well as {@code ConfigValue}.
+ */
+@NullMarked
+package org.openqa.selenium.print;
+
+import org.jspecify.annotations.NullMarked;
diff --git a/java/src/org/openqa/selenium/remote/service/DriverService.java b/java/src/org/openqa/selenium/remote/service/DriverService.java
index 11aacd3677441..3276498d3a315 100644
--- a/java/src/org/openqa/selenium/remote/service/DriverService.java
+++ b/java/src/org/openqa/selenium/remote/service/DriverService.java
@@ -17,6 +17,7 @@
 
 package org.openqa.selenium.remote.service;
 
+import static java.util.Collections.emptyList;
 import static java.util.Collections.emptyMap;
 import static java.util.concurrent.TimeUnit.SECONDS;
 import static org.openqa.selenium.concurrent.ExecutorServices.shutdownGracefully;
@@ -117,8 +118,8 @@ protected DriverService(
       this.executable = executable.getCanonicalPath();
     }
     this.timeout = timeout;
-    this.args = args;
-    this.environment = environment;
+    this.args = args == null ? emptyList() : List.copyOf(args);
+    this.environment = environment == null ? emptyMap() : Map.copyOf(environment);
 
     this.url = getUrl(port);
   }
diff --git a/java/src/org/openqa/selenium/safari/AddHasPermissions.java b/java/src/org/openqa/selenium/safari/AddHasPermissions.java
index 96e49bdb54084..6aa4572387a89 100644
--- a/java/src/org/openqa/selenium/safari/AddHasPermissions.java
+++ b/java/src/org/openqa/selenium/safari/AddHasPermissions.java
@@ -67,21 +67,15 @@ public void setPermissions(String permission, boolean value) {
 
       @Override
       public Map<String, Boolean> getPermissions() {
-        Object resultObject = executeMethod.execute(GET_PERMISSIONS, null);
+        Map<?, ?> resultMap = executeMethod.executeRequired(GET_PERMISSIONS, null);
 
-        if (resultObject instanceof Map<?, ?>) {
-          Map<?, ?> resultMap = (Map<?, ?>) resultObject;
-          Map<String, Boolean> permissionMap = new HashMap<>();
-          for (Map.Entry<?, ?> entry : resultMap.entrySet()) {
-            if (entry.getKey() instanceof String && entry.getValue() instanceof Boolean) {
-              permissionMap.put((String) entry.getKey(), (Boolean) entry.getValue());
-            }
+        Map<String, Boolean> permissionMap = new HashMap<>();
+        for (Map.Entry<?, ?> entry : resultMap.entrySet()) {
+          if (entry.getKey() instanceof String && entry.getValue() instanceof Boolean) {
+            permissionMap.put((String) entry.getKey(), (Boolean) entry.getValue());
           }
-          return permissionMap;
-        } else {
-          throw new IllegalStateException(
-              "Unexpected result type: " + resultObject.getClass().getName());
         }
+        return permissionMap;
       }
     };
   }
diff --git a/java/src/org/openqa/selenium/safari/SafariDriverInfo.java b/java/src/org/openqa/selenium/safari/SafariDriverInfo.java
index 3f9967db274d4..bfd408716a3fb 100644
--- a/java/src/org/openqa/selenium/safari/SafariDriverInfo.java
+++ b/java/src/org/openqa/selenium/safari/SafariDriverInfo.java
@@ -22,7 +22,6 @@
 
 import com.google.auto.service.AutoService;
 import java.util.Optional;
-import java.util.logging.Logger;
 import org.openqa.selenium.Capabilities;
 import org.openqa.selenium.ImmutableCapabilities;
 import org.openqa.selenium.Platform;
@@ -35,8 +34,6 @@
 @AutoService(WebDriverInfo.class)
 public class SafariDriverInfo implements WebDriverInfo {
 
-  private static final Logger LOG = Logger.getLogger(SafariDriverInfo.class.getName());
-
   @Override
   public String getDisplayName() {
     return "Safari";
diff --git a/java/src/org/openqa/selenium/safari/SafariDriverService.java b/java/src/org/openqa/selenium/safari/SafariDriverService.java
index 19c6e29480cc4..52d3d7bc00f96 100644
--- a/java/src/org/openqa/selenium/safari/SafariDriverService.java
+++ b/java/src/org/openqa/selenium/safari/SafariDriverService.java
@@ -68,7 +68,7 @@ public SafariDriverService(
       @Nullable List<String> args,
       @Nullable Map<String, String> environment)
       throws IOException {
-    super(executable, port, timeout, List.copyOf(args), Map.copyOf(environment));
+    super(executable, port, timeout, args, environment);
   }
 
   public String getDriverName() {
diff --git a/java/src/org/openqa/selenium/safari/SafariOptions.java b/java/src/org/openqa/selenium/safari/SafariOptions.java
index b9bda31f9259b..ab390e6b99c25 100644
--- a/java/src/org/openqa/selenium/safari/SafariOptions.java
+++ b/java/src/org/openqa/selenium/safari/SafariOptions.java
@@ -23,6 +23,7 @@
 
 import java.util.Collections;
 import java.util.Set;
+import org.jspecify.annotations.Nullable;
 import org.openqa.selenium.Capabilities;
 import org.openqa.selenium.WebDriverException;
 import org.openqa.selenium.internal.Require;
@@ -105,7 +106,7 @@ public SafariOptions setAutomaticInspection(boolean automaticInspection) {
   }
 
   public boolean getAutomaticProfiling() {
-    return Boolean.TRUE.equals(is(Option.AUTOMATIC_PROFILING));
+    return is(Option.AUTOMATIC_PROFILING);
   }
 
   /**
@@ -144,6 +145,7 @@ protected Set<String> getExtraCapabilityNames() {
     return Collections.emptySet();
   }
 
+  @Nullable
   @Override
   protected Object getExtraCapability(String capabilityName) {
     return null;
diff --git a/java/src/org/openqa/selenium/safari/SafariTechPreviewDriverService.java b/java/src/org/openqa/selenium/safari/SafariTechPreviewDriverService.java
index 01f15fc063df2..d6d03d8f172b9 100644
--- a/java/src/org/openqa/selenium/safari/SafariTechPreviewDriverService.java
+++ b/java/src/org/openqa/selenium/safari/SafariTechPreviewDriverService.java
@@ -29,6 +29,7 @@
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
+import org.jspecify.annotations.Nullable;
 import org.openqa.selenium.Capabilities;
 import org.openqa.selenium.WebDriverException;
 import org.openqa.selenium.net.PortProber;
@@ -66,7 +67,7 @@ public SafariTechPreviewDriverService(
       List<String> args,
       Map<String, String> environment)
       throws IOException {
-    super(executable, port, timeout, List.copyOf(args), Map.copyOf(environment));
+    super(executable, port, timeout, args, environment);
   }
 
   public String getDriverName() {
@@ -114,7 +115,7 @@ public static class Builder
       extends DriverService.Builder<
           SafariTechPreviewDriverService, SafariTechPreviewDriverService.Builder> {
 
-    private Boolean diagnose;
+    @Nullable private Boolean diagnose;
 
     @Override
     public int score(Capabilities capabilities) {
diff --git a/java/src/org/openqa/selenium/safari/package-info.java b/java/src/org/openqa/selenium/safari/package-info.java
new file mode 100644
index 0000000000000..6684283ee6752
--- /dev/null
+++ b/java/src/org/openqa/selenium/safari/package-info.java
@@ -0,0 +1,50 @@
+// Licensed to the Software Freedom Conservancy (SFC) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The SFC licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+/**
+ * Mechanisms to configure and run selenium via the command line. There are two key classes {@link
+ * org.openqa.selenium.cli.CliCommand} and {@link org.openqa.selenium.grid.config.HasRoles}.
+ * Ultimately, these are used to build a {@link org.openqa.selenium.grid.config.Config} instance,
+ * for which there are strongly-typed role-specific classes that use a {@code Config}, such as
+ * {@link org.openqa.selenium.grid.node.docker.DockerOptions}.
+ *
+ * <p>Assuming your {@code CliCommand} extends {@link org.openqa.selenium.grid.TemplateGridCommand},
+ * the process for building the set of flags to use is:
+ *
+ * <ol>
+ *   <li>The default flags are added (these are {@link org.openqa.selenium.grid.server.HelpFlags}
+ *       and {@link org.openqa.selenium.grid.config.ConfigFlags}
+ *   <li>{@link java.util.ServiceLoader} is used to find all implementations of {@link
+ *       org.openqa.selenium.grid.config.HasRoles} where {@link
+ *       org.openqa.selenium.grid.config.HasRoles#getRoles()} is contained within {@link
+ *       org.openqa.selenium.cli.CliCommand#getConfigurableRoles()}.
+ *   <li>Finally all flags returned by {@link
+ *       org.openqa.selenium.grid.TemplateGridCommand#getFlagObjects()} are added.
+ * </ol>
+ *
+ * <p>The flags are then used by JCommander to parse the command arguments. Once that's done, the
+ * raw flags are converted to a {@link org.openqa.selenium.grid.config.Config} by combining all of
+ * the flag objects with system properties and environment variables. This implies that each flag
+ * object has annotated each field with {@link org.openqa.selenium.grid.config.ConfigValue}.
+ *
+ * <p>Ultimately, this means that flag objects have all (most?) fields annotated with JCommander's
+ * {@link com.beust.jcommander.Parameter} annotation as well as {@code ConfigValue}.
+ */
+@NullMarked
+package org.openqa.selenium.safari;
+
+import org.jspecify.annotations.NullMarked;