I recently got an offer from the PreserVim Github organization to take over maintenance of my Markdown Vim plugin and that is its new home. PreserVim adopts Vim plugins that are going unmaintained and tries to at least protect them from bitrot.
I haven't had time to work on vim-markdown in years, but ever since I posted it on Github in 2009 it has lived a life of its own. Contributors took it from a simple syntax file to a full-blown plugin with some awesome features like the table of contents and header increase and decrease commands. I think mine was the first Markdown syntax file for Vim and for a while it was included in the Debian Vim package. After I let it languish a bit, Tim Pope's excellent plugin became the standard and is included in the official Vim distributions.
Here's hoping vim-markdown does well under PreserVim. Maybe I'll even have time to make a few contributions.