let's update some of these links and add new links to blockscout (open source!)

public/content/developers/docs/data-and-analytics/index.md

@@ -20,7 +20,7 @@ In terms of architectural fundamentals, understanding what an [API](https://www.
 
 Many [Block Explorers](/developers/docs/data-and-analytics/block-explorers/) offer [RESTful](https://www.wikipedia.org/wiki/Representational_state_transfer) [API](https://www.wikipedia.org/wiki/API) gateways that will provide developers visibility into real-time data on blocks, transactions, validators, accounts, and other onchain activity.
 
-Developers can then process and transform this data to give their users unique insights and interactions with the [blockchain](/glossary/#blockchain). For example, [Etherscan](https://etherscan.io) provides execution and consensus data for every 12s slot.
+Developers can then process and transform this data to give their users unique insights and interactions with the [blockchain](/glossary/#blockchain). For example, [Etherscan](https://etherscan.io) and [Blockscout](https://eth.blockscout.com) provide execution and consensus data for every 12s slot.
 
 ## The Graph {#the-graph}
 
@@ -54,6 +54,7 @@ EVM Query Language (EQL) is an SQL-like language designed to query EVM (Ethereum
 - [Graph Network Overview](https://thegraph.com/docs/en/about/network/)
 - [Graph Query Playground](https://thegraph.com/explorer/subgraph/graphprotocol/graph-network-mainnet?version=current)
 - [API code examples on EtherScan](https://etherscan.io/apis#contracts)
+- [API documentation on Blockscout](https://docs.blockscout.com/devs/apis)
 - [Beaconcha.in Beacon Chain explorer](https://beaconcha.in)
 - [Dune Basics](https://docs.dune.com/#dune-basics)
 - [EVM Query Language](https://eql.sh/blog/alpha-release-notes) 

public/content/developers/docs/gas/index.md

@@ -125,6 +125,7 @@ Layer 2 scaling is a primary initiative to greatly improve gas costs, user exper
 If you want to monitor gas prices, so you can send your ETH for less, you can use many different tools such as:
 
 - [Etherscan](https://etherscan.io/gastracker) _Transaction gas price estimator_
+- [Blockscout](https://eth.blockscout.com/gas-tracker) _Open source transaction gas price estimator_
 - [ETH Gas Tracker](https://www.ethgastracker.com/) _Monitor and track the Ethereum, and L2 gas prices to reduce transaction fees and save money_
 - [Blocknative ETH Gas Estimator](https://chrome.google.com/webstore/detail/blocknative-eth-gas-estim/ablbagjepecncofimgjmdpnhnfjiecfm) _Gas estimating Chrome extension supporting both Type 0 legacy transactions and Type 2 EIP-1559 transactions._
 - [Cryptoneur Gas Fees Calculator](https://www.cryptoneur.xyz/gas-fees-calculator) _Calculate gas fees in your local currency for different transaction types on Mainnet, Arbitrum, and Polygon._

public/content/developers/docs/intro-to-ether/index.md

@@ -38,7 +38,7 @@ Ether is minted as a reward for each block proposed and at every epoch checkpoin
 
 As well as creating ether through block rewards, ether can be destroyed through a process called 'burning'. When ether gets burned, it gets removed from circulation permanently.
 
-Ether burn occurs in every transaction on Ethereum. When users pay for their transactions, a base gas fee, set by the network according to transactional demand, gets destroyed. This, coupled with variable block sizes and a maximum gas fee, simplifies transaction fee estimation on Ethereum. When network demand is high, [blocks](https://etherscan.io/block/12965263) can burn more ether than they mint, effectively offsetting ether issuance.
+Ether burn occurs in every transaction on Ethereum. When users pay for their transactions, a base gas fee, set by the network according to transactional demand, gets destroyed. This, coupled with variable block sizes and a maximum gas fee, simplifies transaction fee estimation on Ethereum. When network demand is high, [blocks](https://eth.blockscout.com/block/22580057) can burn more ether than they mint, effectively offsetting ether issuance.
 
 Burning the base fee hinders a block producer's ability to manipulate transactions. For example, if block producers received the base fee, they could include their own transactions for free and raise the base fee for everyone else. Alternatively, they could refund the base fee to some users offchain, leading to a more opaque and complex transaction fee market.
 
@@ -67,7 +67,7 @@ When the recipient address is a [smart contract](/developers/docs/smart-contract
 
 Users can query the ether balance of any [account](/developers/docs/accounts/) by inspecting the account's `balance` field, which shows ether holdings denominated in wei.
 
-[Etherscan](https://etherscan.io) is a popular tool to inspect address balances via a web-based application. For example, [this Etherscan page](https://etherscan.io/address/0xde0b295669a9fd93d5f28d9ec85e40f4cb697bae) shows the balance for the Ethereum Foundation. Account balances can also be queried using wallets or directly by making requests to nodes.
+[Etherscan](https://etherscan.io) and [Blockscout](https://eth.blockscout.com) are popular tools to inspect address balances via web-based applications. For example, [this Blockscout page](https://eth.blockscout.com/address/0xde0B295669a9FD93d5F28D9Ec85E40f4cb697BAe) shows the balance for the Ethereum Foundation. Account balances can also be queried using wallets or directly by making requests to nodes.
 
 ## Further reading {#further-reading}
 

public/content/developers/docs/mev/index.md

@@ -26,7 +26,7 @@ With that, for some highly competitive MEV opportunities, such as [DEX arbitrage
 
 This dynamic has made being good at "gas golfing" — programming transactions so that they use the least amount of gas — a competitive advantage, because it allows searchers to set a higher gas price while keeping their total gas fees constant (since gas fees = gas price \* gas used).
 
-A few well-known gas golf techniques include: using addresses that start with a long string of zeroes (e.g. [0x0000000000C521824EaFf97Eac7B73B084ef9306](https://etherscan.io/address/0x0000000000c521824eaff97eac7b73b084ef9306)) since they take less space (and hence gas) to store; and leaving small [ERC-20](/developers/docs/standards/tokens/erc-20/) token balances in contracts, since it costs more gas to initialize a storage slot (the case if the balance is 0) than to update a storage slot. Finding more techniques to reduce gas usage is an active area of research among searchers.
+A few well-known gas golf techniques include: using addresses that start with a long string of zeroes (e.g. [0x0000000000C521824EaFf97Eac7B73B084ef9306](https://eth.blockscout.com/address/0x0000000000C521824EaFf97Eac7B73B084ef9306)) since they take less space (and hence gas) to store; and leaving small [ERC-20](/developers/docs/standards/tokens/erc-20/) token balances in contracts, since it costs more gas to initialize a storage slot (the case if the balance is 0) than to update a storage slot. Finding more techniques to reduce gas usage is an active area of research among searchers.
 
 ### Generalized frontrunners {#mev-extraction-generalized-frontrunners}
 
@@ -46,7 +46,7 @@ MEV emerges on the blockchain in a few ways.
 
 It works like this: if two DEXes are offering a token at two different prices, someone can buy the token on the lower-priced DEX and sell it on the higher-priced DEX in a single, atomic transaction. Thanks to the mechanics of the blockchain, this is true, riskless arbitrage.
 
-[Here's an example](https://etherscan.io/tx/0x5e1657ef0e9be9bc72efefe59a2528d0d730d478cfc9e6cdd09af9f997bb3ef4) of a profitable arbitrage transaction where a searcher turned 1,000 ETH into 1,045 ETH by taking advantage of different pricing of the ETH/DAI pair on Uniswap vs. Sushiswap.
+[Here's an example](https://eth.blockscout.com/tx/0x5e1657ef0e9be9bc72efefe59a2528d0d730d478cfc9e6cdd09af9f997bb3ef4) of a profitable arbitrage transaction where a searcher turned 1,000 ETH into 1,045 ETH by taking advantage of different pricing of the ETH/DAI pair on Uniswap vs. Sushiswap.
 
 ### Liquidations {#mev-examples-liquidations}
 
@@ -78,7 +78,7 @@ However, since NFT transactions happen on the same blockchain shared by all othe
 
 For example, if there's a popular NFT drop and a searcher wants a certain NFT or set of NFTs, they can program a transaction such that they are the first in line to buy the NFT, or they can buy the entire set of NFTs in a single transaction. Or if an NFT is [mistakenly listed at a low price](https://www.theblockcrypto.com/post/113546/mistake-sees-69000-cryptopunk-sold-for-less-than-a-cent), a searcher can frontrun other purchasers and snap it up for cheap.
 
-One prominent example of NFT MEV occurred when a searcher spent $7 million to [buy](https://etherscan.io/address/0x650dCdEB6ecF05aE3CAF30A70966E2F395d5E9E5) every single Cryptopunk at the price floor. A blockchain researcher [explained on Twitter](https://twitter.com/IvanBogatyy/status/1422232184493121538) how the buyer worked with an MEV provider to keep their purchase secret.
+One prominent example of NFT MEV occurred when a searcher spent $7 million to [buy](https://eth.blockscout.com/address/0x650dCdEB6ecF05aE3CAF30A70966E2F395d5E9E5?tab=txs) every single Cryptopunk at the price floor. A blockchain researcher [explained on Twitter](https://twitter.com/IvanBogatyy/status/1422232184493121538) how the buyer worked with an MEV provider to keep their purchase secret.
 
 ### The long tail {#mev-examples-long-tail}
 

public/content/developers/docs/scaling/optimistic-rollups/index.md

@@ -94,7 +94,7 @@ The `calldata` keyword is also used in Solidity to pass arguments to a smart con
 
 In the context of optimistic rollups, `calldata` is used to send compressed transaction data to the onchain contract. The rollup operator adds a new batch by calling the required function in the rollup contract and passing the compressed data as function arguments. Using `calldata` reduces user fees since most costs that rollups incur come from storing data onchain.
 
-Here is [an example](https://etherscan.io/tx/0x9102bfce17c58b5fc1c974c24b6bb7a924fb5fbd7c4cd2f675911c27422a5591) of a rollup batch submission to show how this concept works. The sequencer invoked the `appendSequencerBatch()` method and passed the compressed transaction data as inputs using `calldata`.
+Here is [an example](https://eth.blockscout.com/tx/0x9102bfce17c58b5fc1c974c24b6bb7a924fb5fbd7c4cd2f675911c27422a5591) of a rollup batch submission to show how this concept works. The sequencer invoked the `appendSequencerBatch()` method and passed the compressed transaction data as inputs using `calldata`.
 
 Some rollups now use blobs to post batches of transactions to Ethereum. 
 

public/content/developers/docs/smart-contracts/verifying/index.md

@@ -80,6 +80,12 @@ Etherscan is the most used tool for verifying contracts. However, Etherscan's co
 
 [More on verifying contracts on Etherscan](https://medium.com/etherscan-blog/verifying-contracts-on-etherscan-f995ab772327).
 
+### Blockscout {#blockscout}
+
+[Blockscout](https://blockscout.com/) is an open-source blockchain explorer that also provides a [contract verification service](https://eth.blockscout.com/contract-verification) for smart contract developers and users. As an open-source alternative, Blockscout offers transparency in how verification is performed and enables community contributions to improve the verification process.
+
+Similar to other verification services, Blockscout allows you to verify your contract's source code by recompiling the bytecode and comparing it with the deployed contract. Once verified, your contract receives verification status and the source code becomes publicly available for auditing and interaction. Verified contracts are also listed in Blockscout's [verified contracts repository](https://eth.blockscout.com/verified-contracts) for easy browsing and discovery.
+
 ### Sourcify {#sourcify}
 
 [Sourcify](https://sourcify.dev/#/verifier) is another tool for verifying contracts that is open-sourced and decentralized. It is not a block explorer and only verifies contracts on [different EVM based networks](https://docs.sourcify.dev/docs/chains). It acts as a public infrastructure for other tools to build on top of it, and aims to enable more human-friendly contract interactions using the [ABI](/developers/docs/smart-contracts/compiling/#web-applications) and [NatSpec](https://docs.soliditylang.org/en/v0.8.15/natspec-format.html) comments found in the metadata file.

public/content/developers/tutorials/erc20-annotated-code/index.md

@@ -92,7 +92,7 @@ more valuable than it actually is. However, that fear ignores the true nature of
 every node. To achieve this, every contract's machine language code and storage is available on every node. While you are not required to publish the Solidity
 code for your contract, nobody would take you seriously unless you publish the source code and the version of Solidity with which it was complied, so it can
 be verified against the machine language code you provided.
-For example, see [this contract](https://etherscan.io/address/0xa530F85085C6FE2f866E7FdB716849714a89f4CD#code).
+For example, see [this contract](https://eth.blockscout.com/address/0xa530F85085C6FE2f866E7FdB716849714a89f4CD?tab=contract).
 
  
 

public/content/developers/tutorials/erc20-with-safety-rails/index.md

@@ -47,7 +47,7 @@ Before we can add the safety rail functionality we need an ERC-20 contract. In t
 
 Users sometimes send tokens to the wrong address. While we cannot read their minds to know what they meant to do, there are two error types that happen a lot and are easy to detect:
 
-1. Sending the tokens to the contract's own address. For example, [Optimism's OP token](https://optimism.mirror.xyz/qvd0WfuLKnePm1Gxb9dpGchPf5uDz5NSMEFdgirDS4c) managed to accumulate [over 120,000](https://optimistic.etherscan.io/address/0x4200000000000000000000000000000000000042#tokentxns) OP tokens in less than two months. This represents a significant amount of wealth that presumably people just lost.
+1. Sending the tokens to the contract's own address. For example, [Optimism's OP token](https://optimism.mirror.xyz/qvd0WfuLKnePm1Gxb9dpGchPf5uDz5NSMEFdgirDS4c) managed to accumulate [over 120,000](https://optimism.blockscout.com/address/0x4200000000000000000000000000000000000042) OP tokens in less than two months. This represents a significant amount of wealth that presumably people just lost.
 
 2. Sending the tokens to an empty address, one that doesn't correspond to an [externally owned account](/developers/docs/accounts/#externally-owned-accounts-and-key-pairs) or a [smart contract](/developers/docs/smart-contracts). While I don't have statistics on how often this happens, [one incident could have cost 20,000,000 tokens](https://gov.optimism.io/t/message-to-optimism-community-from-wintermute/2595).
 
@@ -125,7 +125,7 @@ Sometimes it is useful to have an administrator that can undo mistakes. To reduc
 1. Freezing and unfreezing accounts. This can be useful, for example, when an account might be compromised.
 2. Asset cleanup.
 
-   Sometimes frauds send fraudulent tokens to the real token's contract to gain legitimacy. For example, [see here](https://optimistic.etherscan.io/token/0x2348b1a1228ddcd2db668c3d30207c3e1852fbbe?a=0x4200000000000000000000000000000000000042). The legitimate ERC-20 contract is [0x4200....0042](https://optimistic.etherscan.io/address/0x4200000000000000000000000000000000000042). The scam that pretends to be it is [0x234....bbe](https://optimistic.etherscan.io/address/0x2348b1a1228ddcd2db668c3d30207c3e1852fbbe).
+   Sometimes frauds send fraudulent tokens to the real token's contract to gain legitimacy. For example, [see here](https://optimism.blockscout.com/token/0x2348B1a1228DDCd2dB668c3d30207c3E1852fBbe?tab=holders). The legitimate ERC-20 contract is [0x4200....0042](https://optimism.blockscout.com/token/0x4200000000000000000000000000000000000042). The scam that pretends to be it is [0x234....bbe](https://optimism.blockscout.com/token/0x2348B1a1228DDCd2dB668c3d30207c3E1852fBbe).
 
    It is also possible that people send legitimate ERC-20 tokens to our contract by mistake, which is another reason to want to have a way to get them out.
 

public/content/developers/tutorials/how-to-mint-an-nft/index.md

@@ -109,7 +109,7 @@ Once you’re done editing the JSON file, save it and upload it to Pinata, follo
 
 ## Step 5: Create an instance of your contract {#instance-contract}
 
-Now, to interact with our contract, we need to create an instance of it in our code. To do so we’ll need our contract address which we can get from the deployment or [Etherscan](https://sepolia.etherscan.io/) by looking up the address you used to deploy the contract.
+Now, to interact with our contract, we need to create an instance of it in our code. To do so we'll need our contract address which we can get from the deployment or [Blockscout](https://eth-sepolia.blockscout.com/) by looking up the address you used to deploy the contract.
 
 ![View your contract address on Etherscan](./view-contract-etherscan.png)
 
@@ -316,7 +316,7 @@ Now, run `node scripts/mint-nft.js` to deploy your NFT. After a couple of second
 
     Check Alchemy's Mempool to view the status of your transaction!
 
-Next, visit your [Alchemy mempool](https://dashboard.alchemyapi.io/mempool) to see the status of your transaction (whether it’s pending, mined, or got dropped by the network). If your transaction got dropped, it’s also helpful to check [Sepolia Etherscan](https://sepolia.etherscan.io/) and search for your transaction hash.
+Next, visit your [Alchemy mempool](https://dashboard.alchemyapi.io/mempool) to see the status of your transaction (whether it’s pending, mined, or got dropped by the network). If your transaction got dropped, it’s also helpful to check [Blockscout](https://eth-sepolia.blockscout.com/) and search for your transaction hash.
 
 ![View your NFT transaction hash on Etherscan](./view-nft-etherscan.png)_View your NFT transaction hash on Etherscan_
 

public/content/developers/tutorials/learn-foundational-ethereum-topics-with-sql/index.md

@@ -20,11 +20,11 @@ Onchain data can help us understand Ethereum, the network, and as an economy for
 
 A user’s journey on Ethereum starts with initializing a user-controlled account or an entity with an ETH balance. There are two account types - user-controlled or a smart contract (see [ethereum.org](/developers/docs/accounts/)).
 
-Any account can be viewed on a block explorer like [Etherscan](https://etherscan.io/). Block explorers are a portal to Ethereum’s data. They display, in real-time, data on blocks, transactions, miners, accounts and other onchain activity (see [here](/developers/docs/data-and-analytics/block-explorers/)).
+Any account can be viewed on a block explorer like [Etherscan](https://etherscan.io/) or [Blockscout](https://eth.blockscout.com/). Block explorers are a portal to Ethereum's data. They display, in real-time, data on blocks, transactions, miners, accounts and other onchain activity (see [here](/developers/docs/data-and-analytics/block-explorers/)).
 
 However, a user may wish to query the data directly to reconcile the information provided by external block explorers. [Dune Analytics](https://duneanalytics.com/) provides this capability to anyone with some knowledge of SQL.
 
-For reference, the smart contract account for the Ethereum Foundation (EF) can be viewed on [Etherscan](https://etherscan.io/address/0xde0b295669a9fd93d5f28d9ec85e40f4cb697bae).
+For reference, the smart contract account for the Ethereum Foundation (EF) can be viewed on [Blockscout](https://eth.blockscout.com/address/0xde0B295669a9FD93d5F28D9Ec85E40f4cb697BAe).
 
 One thing to note is that all accounts, including the EF’s, have a public address that can be used to send and receive transactions.
 
@@ -64,7 +64,7 @@ This will yield the same information as provided on Etherscan's transaction page
 
 ![](./etherscan_view.png)
 
-[EF's contract page on Etherscan.](https://etherscan.io/address/0xde0B295669a9FD93d5F28D9Ec85E40f4cb697BAe)
+[EF's contract page on Blockscout.](https://eth.blockscout.com/address/0xde0B295669a9FD93d5F28D9Ec85E40f4cb697BAe)
 
 #### Dune Analytics {#dune-analytics}