The full InfinityDB 4 trial edition, most recent version.
InfinityDB is a Java embedded DBMS with a unique very fast, extremely flexible and simple API based on an ‘ItemSpace’, along with a wrapper to make the model accessible as a Java ConcurrentNavigableMap. It has optimistic transactions, data compression, multi-core concurrency, rugged I/O without a log, instant restart, a single-file data store, easy backwards data structure compatibility without upgrade scripts, and zero installation management effor. Developer productivity is almost instant. There are many utilities and example code.
Version 4.1.x now includes standard Java Microbenchmarking Harness performance tests, showing its tremendous in-memory performance characteristics.
After the trial period ends, an Exception is thrown on initialization.