TextMate comes with support for Markdown and version control (Git, Subversion, etc). OS X only, although I've heard there is a wanna-be clone for Windows.
1) The University of Maryland is only 4 miles from DC, it is 10 miles from the National Mall.
2) MIT is not in the Ivy League. The Ivy League is an athletic conference and not some subjective grouping of elite institutions. Not to say that it isn't at the same level.
www.macromates.com