I've been searching (with little success) for a free/opensource session clustering and replication solution for asp.net. I've run across the usual suspects (indexus sharedcache, memcached), however, each has some limitations.

• Indexus - Very immature, stubbed session interface implementation. Its otherwise a great caching solution, though.
• Memcached - Little replication/failover support without going to a db backend. Several SF.Net projects - All aborted in the early stages... nothing that appears to have any traction, and one which seems to have gone all commercial.
• Microsoft Velocity - Not OSS, but seems nice. Unfortunately, I didn't see where CTP1 supported failover, and there is no clear roadmap for this one. I fear that this one could fall off into the ether like many other MS dev projects.

I am fairly used to the Java world where it is kind of taken for granted that many solutions to problems such as this will be available from the FOSS world.

Are there any suitable alternatives available on the .Net world?