The European Commission granted Oracle an unconditional approval to take over Sun Microsystems, following a controversial and widely criticized examination of the deal.

The deal still awaits approval in other jurisdictions, including Russia and China, but approval in the European Union is a big step forward for a deal hailed by some as transformational for the entire software industry, and by others as the killer of one of the most successful open source programs in the world, the MySQL database.

Last November the Commission, the EU's top antitrust regulator, expressed serious concerns about the planned deal because it would mean that Oracle, the world's largest proprietary database developer, would gain control of MySQL, an open source database division of Sun that has in recent years been stealing market share away from its more expensive rivals: Oracle, IBM and Microsoft.

However, it swept those concerns aside in December after Oracle promised to safeguard MySQL for five years after the deal goes ahead.

Controversially, this pledge was made to vendors, software developers and customers of MySQL, and not to the Commission itself.