You may have heard of it, or you may have not. Either way, OCOL is exactly what the title says, so read it.
It's a pretty great launcher replacer, but it's aged, and has seemingly been abandoned. It still works, but there are some new bugs popping up. Such as it misreading the contents of my bashed patch.
It's a shame to let it go to waste. http://www.tesnexus.com/downloads/file.php?id=10451. Hopefully someone will feel like diving into it and making an update.