The latest musl source is always available via the git revision control system. Efforts are made to keep the master branch in a state that not only compiles and works, but that works at least as well or better than the latest release.
The following command can be used to checkout a copy of the musl git repository:
$ git clone git://git.musl-libc.org/musl
Source and revision history are also browsable online via cgit.
Earlier versions of musl from the alpha and beta series (0.5.0 through 0.8.10) have been moved to a separate page.