From No LJ Ads Wiki

brad sold Danga Interactive and LiveJournal to Six Apart on January 5, 2005 for an undisclosed amount of cash and stock.

You can find the news post on it here (news). Mena Trott made a post about it here. The other two Six Apart links about it are dead; foxfirefey emailed website@sixapart.com about them, but received no response. Evidently, that is because of a redirect not handled (insomnia) and will be looked into.

[edit] Links

• The Cultural Divide between LiveJournal and Six Apart
• Silicon Beat Interview