Contact: peter [at] poeml.de
MirrorBrain is a software I wrote for running high-performance download infrastructures. It is used by a good dozen large and small organizations. Around the world, it handles 20–40 million downloads every day. That's about as much as all downloads that Apple's App Store handles altogether, worldwide. Chances are that you have used MirrorBrain in the past yourself, even if you may not know about it.
A high-level overview presentation is available. For German readers, some friendly folks have contributed a well-written Wikipedia article.
Together with fellow projects working on the Metalink standard, MirrorBrain won an innovation price donated by Sun ($1.000.000 altogether, about $7,000 for Silver nomination).