The current version of Freebox is 0.5. This is considered to be a test release (as will everything before 1.0), so bugs, eratta, missing features, and other problems are to be expected. To the best of my knowledge the release is stable, meaning that it shouldn't crash unnecisarily. If it does, send me the log file and a description of what you were doing.
The current Windows release is 0.5. The necessary libraries are included in the package; it can be unzipped and run from anywhere. No installation is required.
The current Linux release is 0.5. SDL and FMOD must be installed, as they are dynamically linked to Freebox. On my Gentoo box, a simple emerge sdl fmod does the trick. Other distros will have their own procedure for doing the same thing.
This contains the source code for Freebox. Most people will want to get one of the binaries above, unless they need to compile against a different libc or something similar, or they want to work on the code ( hint, hint :-) ). Check out the compiling page for more information.
Old releases can be found here.