CMake 2.6 has been released. See the release announcement. CMake is a very nice cross-platform build tool which does not build itself but instead creates projects for the target platform (Visual Studio projects files for Windows, Makefiles for Linux, etc.).
Pretty nice and it usually "just works". Recently, KDE has switched over to it, and since then I also gave it a try and I must admit so far, it's the best build tool I tried. Aqsis is also using it and it works pretty well so far; supporting Mac OS, Windows and Linux -- this is where I had my first personal contact with CMake.