On Thursday, Twitter announced — by tweet, of course — that it has filed to go public.

That is, Twitter submitted a  S-1 filing to the SEC for a planned IPO.  It did so confidentially, as allowed under the JOBS Act.  Twitter revealed this to the world 3 days ago through its own Twitter account in a brief tweeter…and minutes later, casually tweeted, “Now, back to work.”

Twitter’s IPO plans are sure to be watched closely by the world.  Facebook going public was, of course, an enormous event filled with business and legal questions and activities.