Moveable Type Weblog software developer Six Apart has acquired Danga Interactive, operator of Weblog service LiveJournal, for an undisclosed amount of cash and stock.

With the acquisition, Six Apart, which also operates the TypePad personal Web-logging service, now counts more than 6.5 million customers.

LiveJournal, an online personal journal Web site, offers customers either free or paid subscriptions to a personal publishing Web-logging tool, built on open source software. Every week, more than 860,000 users update their Web logs on LiveJournal, according to a Six Apart press release. LiveJournal's users are mostly in their teens and 20s, younger than users of Six Apart's other products.

As part of Six Apart, LiveJournal will operate as a separate division. Brad Fitzpatrick, Danga's founder, president and lead developer, will join Six Apart as the company's chief architect. Six Apart plans to expand the staff at Danga, and the company doesn't plan any layoffs in the acquisition, with LiveJournal's engineering team moving from Portland, Oregon, to Six Apart's San Francisco headquarters, said Jane Anderson, a Six Apart spokeswoman.

LiveJournal will continue to distribute a large portion of its software under various open source licenses, and Six Apart plans to keep the LiveJournal software separate from its Movable Type and TypePad products, with engineering and support teams for each product.

The acquisition of LiveJournal makes Six Apart the industry's largest independent provider of Web-logging tools, according to company officials. According to a survey released this week by the Pew Internet & American Life Project, more than 8 million US adults now have Weblogs and readership jumped by 58 per cent in 2004.

The acquisition is a natural fit because "both companies are fanatics about Web-logging," LiveJournal founder Fitzpatrick said in a statement.