Here's a nice article details to little known tools in the "mainstream" developer community: Selenium, a browser and web automation framework, and Fitnesse, an acceptance and integration automation solution that uses a Wiki style for managing the tests and data.
To be clear, these are pure integration tests, and not unit tests. They might be using some sort of a unit test framework to do their bidding, but they are testing integrated parts of a full running application, they require configuration of some sort, they take much longer to run, and basically do not meet the the idea of unit tests.
[via .NET Kicks]