The new stable release of Tomcat 6.0.24 represents six months of open source software development. Version 6.0.24 includes a small number of new features, plus a large amount of important bug fixes and enhancements. This release is an incremental bug fix release, but the number of fixes included in this release is high.
Some very nice stuff in Tomcat 6.0.24, particularly surrounding memory leak handling. I haven't run into issues with memory leaks on 6.0.20 in my own applications, but they did a lot of work in that area.
And a biggie--a native installer for 64-bit Windows. Halle-freakin'-lujah! No more grabbing the exes from SVN and overwriting the ones that come with the 32-bit installer.