When's the last time you surfed on over to your Pligg and updated what you were doing for the entire Internet to see?  What about Elgg?  Have you changed your favorite movies to reflect that big blockbuster hit you saw this weekend?  You probably don't have to, because all of your friends using the Tweetero client on their iPhones could just log on and see exactly what you were up to.  Or not.  Because you aren't on Twitter -- you're on Identi.ca, the open-source equivalent of the popular messaging program.

Unlike the open-source software world, where even the smallest gems of programs can find a meaningful existence, the open-source social networking world depends on people.  Masses of people.  You can't just launch a new social networking platform and expect it to flourish if it doesn't have a decently sized audience. And you're never going to pull away the users that are already comfortable on their existing Web 2.0 platforms if you just imitate the best practices of the current litany of sites.  But that's what's happening in the open-source social networking world right now.  There's a healthy mix of innovation and duplication, giving some segments of the online world new and interesting applications... and others with their 25th version of Twitter.

Wordpress founder Matt Mullenweg says it best: "There’s been an explosion of social activity on the web, it’s probably the most important trend of the past few years, but there’s been a dearth of Open Source tools that enable the social web."  I agree, but I'd be willing to take the argument one step further and say that there are plenty of open source tools to allow a person, or company, to experiment with the social networking space akin to a MySpace or a Facebook.  One of the latest Wordpress side projects, Buddypress, allows one to tap into that very environment.  But there are certainly other open-source social networking tools: both Elgg and Pligg, mentioned previously, are strong examples.

And while an application like Elgg has found strong support in individual use scenarios, there has yet to exist an open-source social community on the scale of a Facebook, Twitter, or MySpace.  But that's precisely the point.  An open-source model is not going to find success in the modern social Web because it's competing against the prevailing mindsets of the users that populate existing environments.  In short, they aren't going to move.  They aren't going to move because they're already established on a successful, sprawling social network.  And that mindset is going to carry over even if, through some awesome power of the development community, the open-source social network offers increased functionality to the established community. k

It's important to distinguish that I'm only talking about social networks at this point.  Open-source applications that involve some element of community, but are not social networks in the true sense of the phrase, are spared from the users-dropping-their-anchors-and-staying scenario.  Just consider all of the different CMS and photo-themed Web applications that are open, useful, and popular.  Just because Flickr or Smugmug exists doesn't mean that there's no market for Coppermine.  The commercial arm of MoveableType certainly hasn't cornered the world on blogging software, nor has it pushed out the open-source equivalents.

But that's because these entities don't depend on a community to thrive, per se.  Ten people in the entire world can install Wordpress and that application would still have some functional use.  A thousand people could switch to Identi.ca, and I can guarantee that not a peep would be heard from the millions of Twitter users worldwide.  I really hate the "community is king" jargon, but when it comes to social networks, it's true.  And what's easier for an aspiring developer to do: build a competing social network from the ground up, or find new ways to make use of these existing, sprawling communities to further an open agenda?  Why build an Ubuntu network if you can leverage the power of the existing herd where they already are?

So what's the takeaway?  When open-source is just a vision or a programming goal, it can achieve its goals regardless of the size of the community that grows around it.  But when you throw social networking into the mix, open source development gets hit with a wrench.  While a number of interesting open alternatives to common, proprietary social networking platforms exist today, they are never going to be able to carry the kind of clout of the big social networks.  An open-source social network has to be the game-changing application like Twitter was to the normal Web back in 2006 -- you can't just copy the best and expect to find much success.