I am no longer a regular user of either Quicksilver or Remember The Milk, so I do not have plans to continue development on RTM for QS. Sorry.
Remember The Milk for Quicksilver is an open source application released under the BSD open source license. You can get the source code by subversion checkout. See the Google Code project page for details.
This software uses the Remember The Milk API, but is neither affiliated with nor certified by Remember The Milk.