Ohloh Project Analysis
ModeShape is an elastic, in-memory, and strongly-consistent hierarchical database. It is fast, scalable, easy to use, and can be schema-less, schema-strict, or anywhere in-between. ModeShape supports transactions, has several query languages, events, versioning and more. Several APIs are available: the primary API is the standard JCR 2.0 API (JSR-283), but there are several others (e.g., RESTful, WebDAV, and JDBC) that expose a subset of the overall functionality.