Built as the storage layer to Akiban Server, Persistit provides extremely fast, highly concurrent direct data access with ACID transactions. Benchmarks show that Persistit is significantly faster than other B+tree engines and can even outperform native-code libraries.

Highlights
  * Free. Persistit is available under the Apache License, Version 2.0.

  * Fast. Persistit supports high-performance object serialization, high
     concurrency for reads and writes, separate long record handling, and a hybrid update
     approach combining in-place and append-only updates.

  * Compact. Persistit's small footprint imposes minimal demands on system resources.

  * Safe. Persistit supports ACID transactions with MVCC concurrency, and requires no
     end-user administration. Visibility into Persistit internals is provided through
     both command-line and swing-based, RMI GUI tools.

  * Rich. The Persistit API is flexible and easy-to-use.

  * Seamless integration. Persistit is implemented purely in Java and minimizes garbage
     collection overhead through stable memory management. The library is easily integrated
     with Java, Groovy, JRuby, Jython and Scala application code, and allows developers to
     leverage state-of-the-art test, debug and IDE tooling.

  * Powerful capabilities. Persistit provides disk-based or in-memory-only trees, garbage
     collection, and support for large databases.

Licensing
  * Persistit is freely available under the the Apache License.

Questions?
  * Support: http://support.akiban.com
  * Email: akiban-user@akiban.com
  * IRC: #akiban on freenode.irc.net