matspca 

High performance and availability, scalable and very flexible pure .NET database. Using VelocityDB saves time and money for all software requiring reliable, high performance data persistence. Any .NET object... More information

Pure, fast and scalable .NET property graph and object hybrid database. No new graph language to learn, all accomplished with a .NET API.

Extensions to VelocityDB for efficient LINQ index/BTree queries, AzureSession file API usage with Microsoft Azure, import/export to/from CSV and JSON, Sync, GeoHash, Compressed Bitmap and RTree.