It’s here: Facebook files for $5 billion IPO

The most highly anticipated initial public offering in today’s tech world is officially happening. Facebook filed S-1 documents with the Securities and Exchange Commission Wednesday afternoon to raise a maximum of $5 billion. According to the filing, Facebook made $3.7 billion in revenue in 2011.

The 10 stories that defined tech in 2011

While 2011 was a busy year for the tech industry, don’t expect things to slow down in 2012. We’ve rounded up some of GigaOM’s biggest stories of the year with a bit of insight on what each will mean for 2012.