JBoss has bought [pdf] Arjuna Technologies for an undisclosed sum.

The acquisition of the transaction processing software company marks a strategic shift for JBoss, which until now has acquired or partnered with open source companies. Arjuna has proprietary software which JBoss will make open source.

Transaction engines help manage a series of related business events that need to occur as a group. For example, a bank might use a transaction engine to ensure that when a payment is transferred between accounts, the credit and debit operations are both completed successfully.

The technology is complex to develop and JBoss bought the Arjuna software, which has been developed over two decades, to speed up its development in the transactional software on the market, said JBoss chief exec Marc Fleury.

Arjuna was originally formed at Newcastle University in the 1980s. It was acquired by Bluestone in 2000 and in turn was acquired by HP in 2001 for a reported $450 million Following HP's merger with Compaq in 2002, HP decided to discontinue its middleware portfolio, prompting wide speculation about where the technologies would end up.

Arjuna will continue to exist as a company, selling its remaining Java messaging product (which was also formerly an HP product) and providing consulting services for both the messaging and transaction products, Little said.

The move by JBoss follows Sun's announcement last week that it plans to make all of its core software products open source.

JBoss plans to release the source code for both products in the first quarter next year and to integrate them with a future version of its Java middleware suite, version 5.0, Fleury said. In the meantime they will be offered as add-on modules for versions 3.0 and 4.0 of the suite, he said.