PEG Launch autopilot. This is intended to be a general-purpose launch autopilot, capable of taking any launch vehicle into a particularly-targeted orbit. It's still very rough, and can't control all launch vehicles, but it does well with the stock Atlantis. When it works, it is an extremely accurate and targetable autopilot.
This is beta-quality code. It works pretty well for me, but is fully capable of CTD or worse, so use at your own risk. Source code is included.
This package also includes the original NASA document describing the PEG algorithm. This autopilot does not yet completely implement this document.