Hacker News - Hacker News is a social news website focusing on computer science and entrepreneurship. It is run by Paul Graham's investment fund and startup incubator, Y Combinator.
Empeopled - Empeopled is a content-sharing community that
Boostlog - A blogging platform for programmers.
DonationCoder - A site for software connoisseurs - featuring the best freeware, donationware, software reviews, and discussions.
Reddit - Reddit gives you the best of the internet in one place. Get a constantly updating feed of breaking news, fun stories, pics, memes, and videos just for you.
Telescope - Telescope is an open-source app that lets you easily set up your own online community.