A few folks are confused by the various release numbers being announced or discussed all at one time, so I thought I'd clarify:
NUnit 2.4.7 is the latest production release of NUnit. It's the one we recommend most people use for your tests. Some fairly critical performance bugs have been fixed in the last few releases, so you should update even if you're only one or two digits back. See what you're missing !
NUnit 3.0 is the planned - but not yet released - next generation NUnit. We call it the NUnit Extended Testing Platform, to distinguish it from the current NUnit Framework. It will provide a superset of the functionality of the current framework and is generally described here. I'll be posting further info on NUnit 3.0 as it progresses.
NUnit 2.5 is release that wasn't originally planned. The 2.4 series was supposed to be followed by 3.0. However, a number of people asked for a quicker release that included features provided by other test frameworks, which are currently missing from NUnit. So 2.5 is now in alpha, with extensions to support data-driven tests, easier exception testing and a number of other goodies. It's also being bundled with pNUnit, an extension that supports distributed parallel tests. See the release notes for details. Watch for the second Alpha release sometime next week.
Hopefully, this will clear things up till we generate some more numbers.
[...] NUnit 2.4.7, 2.5, 3.0: What’s With That? - Charlie Poole clears up any confusion with the version number roadmap for the NUnit unit testing project - sounds like there are interesting features in both 2.5 and 3.0 [...]
Reflective Perspective - Chris Alcock » The Morning Brew #87, Monday, May 5, 2008