Rising from the ashes of the dot com boom, db.* was originally released as open source by a now-defunct software company, which spent millions of dollars on development and documentation. When the company went bust, there was no one to support the development of db.*, and the database fell into obscurity. ITTIA is making it available to the public in order to promote its tech support and consulting business, and to promote Club ITTIA, its embedded database community.
The database license agreement allows db.* to be used, modified and distributed freely on open source operating systems. The license is very similar to the Mozilla license. Developers are not obligated to give away their source code.
db.* has an unusual technical model which distinguishes it from other embedded databases. It uses a combination relational- and network model, allowing application developers to use whatever mix of the two models is most appropriate for his or her application. (See this whitepaper(PDF) for more information about network-model databases.)
Because of its extensive development, db.* has many features one would not expect in a small-footprint database, including multi-user support and transaction processing. There is also an ODBC and XML interface available separately from ITTIA.