Cross-platform embedded database/key-value store for C#

Question

I'm looking for a fast, embeddable key/value store with cursor semantics over key collections (or a simple embeddable DB) that I can use in .NET and mono. Need it to be open-source, would prefer an MIT or Apache style license over a GPL license. Not opposed to a library that needs bindings to be written, as long as binaries are available for both windows and linux.

Options considered:

• SQLite - has bindings and native implementation, but single-threaded and not all that fast
• Embedded InnoDB - no .NET bindings i can find and it's GPLv2
• Berkley DB - no .NET bindings i can find
• Tokyo Cabinet - no .NET bindings i can find and problematic to build on windows
• MadCow Memory-mapped data structures - GPLv2

Is there an option better than the above that i'm missing, or bindings for the above i don't know about?

UPDATE: Used Oracle's official BDB bindings with 4.8 and 5.0 but couldn't get them working under mono. Also had some other issues (C# drivers for BDB are still immature). Wrote a BitCask inspired K/V store called Firkin ( http://github.com/sdether/Firkin ) store and using that now instead.

Answer 1

A quick search for Berkeley DB Bindings for C# turned up - Berkeley DB for .NET

Answer 2

i vote for Berkley DB. it is very fast and wrapper is good. i used it a lot