Insoshi wants to be WordPress for social networks, except built on top of Ruby on Rails instead of PHP.

We covered them in March when they presented at the Spring Y Combinator demo day. Now they’ve officially released their software for public download so anyone can install it on-premise to run their own social networks.

Insoshi is not the first company to release its social networking code. Broadband Mechanics has always emphasized the openness of its PeopleAggregator platform, and even Ning, the most publicized DIY social networking company, will give you the underlying code if you request it.

It’s not even the first Ruby on Rails project to go open source. Lovd By Less appears to have claimed this honor, although Insoshi founder Michael Hartl insists that the code he released under an MIT License in July 2007 should be considered the first RoR social networking open source code. Quibbles about who was first aside, Insoshi certainly has the advantage of having in Hartl a very prominent founder: he wrote RailsSpace, which is considered the book for writing social networks in RoR.

I look forward to seeing whether Insoshi is really able to build the type of developer community that’s associated with names like Mozilla and MySQL. If it manages to pull it off, it will become a very attractive option for organizations that want to run social networks independently.

Check out a test social network built on Insoshi here.

Crunch Network: CrunchGear drool over the sexiest new gadgets and hardware.