For Visual Studio there's ViEmu (http://www.viemu.com/). Unfortunately it is not free, and it is not 100% Vim. I've been using it for 1-2 years now and is really happy with it, as it allows me to do most of what I'm used to from Vim.
I doesn't replace all of VS's key bindings, so you can actually mix VS and Vim commands, which is nice. However, it does make life a little harder if you want to use other plug-ins such as ReSharper and the like.