Sponsoring the Tor Project contributes to Tor’s Bug Smash Fund:

When you are building software, your work is not always about adding new features; often, it's about fixing bugs. We know that our community understands it’s very important to fix bugs we encounter in our software—especially bugs that create security problems. But it can be hard to raise money for this type of work, since maintenance is not as exciting as a cool new feature. That’s why we decided to create our Bug Smash Fund.
The goal of the Bug Smash Fund is to increase the Tor Project’s reserve of funds that allow us to complete maintenance work and smash the bugs necessary to keep Tor Browser, the Tor network, and the many tools that rely on Tor strong, safe, and running smoothly.
When we say maintenance and bugs, we are talking about work that is critical—and that we must pay for. This work includes responding quickly to security bugs, improving test coverage, and keeping up with Mozilla’s ESRs. An entire ecosystem relies on us doing so.
So far, we’ve marked 93 tickets with BugSmashFund. As of today, 66 of those tickets have been closed, and 27 of them are still in progress.
You can help us be prepared for what bugs may come, and in turn, we can better help keep millions of people around the world safe online and an entire ecosystem of tools healthy.