The outgrowth of this was McDipper, a highly performant flash-based cache server that is Memcache protocol compatible. The main design goals of McDipper are to make efficient use of flash storage (i.e. to deliver performance as close to that of the underlying device as possible) and to be a drop-in replacement for Memcached. McDipper has been in active use in production at Facebook for nearly a year.
Mother is the necessity of all invention. That and cash flow.