Need super fast persistence? Prevayler is the free-software Prevalence layer for Java!

Dump your RDBMS and reachitect your system if size of your data can fit into a memory


Performance

Queries with Prevayler are more than 9000 times faster than querying Oracle through JDBC.
Queries with Prevayler are more than 3000 times faster than querying MySQL through JDBC.

http://www.prevayler.org/wiki.jsp

For versioning xstream can be used to serialize as XML

http://xstream.codehaus.org/

Today’s challenges in IT industry

• Producing and maintaining software is very expensive today.
• Productivity is very low. Building a house takes weeks, building applications takes months.
• Quality of the software is still fairly low: buggy software is fairly common and it’s tolerated despite of the impact on productivity (rebooting machine, reinstalling application, compatibility issues etc.)
• Vendor lockup: migrating from one vendor to another is very expensive in terms of labor and licensing cost: training, integration into larger systems. Vendors are abusing it to their advantage by forcing their upgrade cycles, service fees etc.
• Customers are very limited on what they can do with the software and how they use it. They still don’t have a full control over what the buy.