65 MB? For a git browser? Really?
The size is that big because Gitbox is bundled with official Git binaries so you don't have to install anything else. I will see how to bring the size down in the next versions. Anyway, this fact does not affect the performance and does not eat much memory.
The problem is that the bundle contains exactly same binary 104 times (git, git-add, git-apply, etc. are identical files, 1.3MB each). These should be symlinks.
It might be ZIP's fault (doesn't support symlinks AFAIK). I distribute my apps as tar.bz2, and nobody complained yet.
(sorry, cannot reply to you directly: no reply link)