We are switching from SVN to Git soon, though it's unlikely at least for now, that there will be public access. We have a build process, and part of that process is to pull in externals. All extensions have their own version numbers and belong to their own repositories. So, even if we did allow public access, there's more you'd need to do in order to have everything that's in a build. We'll be announcing more details about this and more as we get closer to a 4.0 release.