A principal at Agaric regrettably uses Microsoft Windows as a primary operating system. In fact, though, everything works great for him using the open source integrated development environment Eclipse to develop, including using the eGit plugin-- except when something goes wrong, and my (limited) command line knowledge of Git is useless to help him.
Fortunately, it turns out to be pretty easy to have command-line Git on Windows with Eclipse, it just isn't well documented.