v1.0a5 is the latest official version. Marcello Sega and Marco Vecchiocattivi have created an (as yet) unofficial version 1.0a6. Remember that it is still in the alpha phase of development! It is supposed to be unsupported, being an alpha product, but in practice, I have been supporting users of other alpha versions, so you can sort of forget about that. Nevertheless, it does have bugs.
You can download either its source (650K), or its Win32 DirectX precompiled version (463 KB).
If you are a big fan of Utumno, have either DJGPP or a good Windows compiler installed, and want to either modify it or see how it works, get the source. Otherwise, for more ordinary people,
download the self-extracting installer. This will unpack installation files, install utumno, create a desktop and start menu shortcut, and clean up and remove the installation files.
If you are using Windows 95 or Windows NT 4.0, get the DirectX version. You should have at least DirectX 3 installed. DirectX 5 is recommended, but unfortunately NT users can't get it.
Note for people playing with the source: I compile the Win32 version using Visual C++ 5.0. Get it if you are serious about Windows programming. Other compilers will probably have minor compatibility problems with the Utumno source.
Linux users can get the version 1.0a6 source or version 1.0a6 for Linux compressed package.