You can always download the latest distribution from here.
Debian and Ubuntu users, for your convenience, there is deb packages available on boo's google group files page.
Our choses source repository is Subversion (SVN). If you are new to Subversion, check it out , then see the boo Source page for instructions on getting the latest build of boo. You can download a tarball via the web interface here.
If you decide to download a binary distribution, unzip Boo to a directory and you'll find booc.exe, the compiler, and booish.exe, the interpreter. Remember you will need to have .NET or MONO installed. You may want to add the boo directory to your path.
If you decide to download a source distribution read the build instructions. You can also grab the latest sources from the Subversion repository.