Building on Erbit or Off of Erbit?

Herbert is an open source, decentralised version of the popular e-mail service erbit. It's designed to be used by people who want to build their own websites and apps on top of it. Herbert was founded in 2012 as a foundation for other companies that wanted to use its technology but couldn't get off the ground. The company has now raised $100m (£62 million) from investors so far this year.