IntenseDebate, a commenting plugin for popular blog platforms like WordPress, Blogger, and TypePad, just announced that it will allow third-party developers to write plugins on top of its new Plugin API. The company launched this new feature today with plugins for PollDaddy, Seesmic, and YouTube. Publishers can easily activate these new plugins from their IntenseDebate dashboard.

The current crop of plugins was created by IntenseDebate’s own programmers, but it will be interesting to see what new ways of expanding and enhancing comments the developer community can come up with. Adding videos and polls, while interesting, will surely only be the beginning.
Competition
The market for commenting services has become quite competitive lately. Yahoo, for example, just announced an alliance with JS-Kit yesterday, and Facebook also just released a commenting plugin based on Facebook Connect as its first social widget. Other competitors of IntenseDebate are obviously Disqus, which already offers integration with Seesmic, and Google’s Friend Connect. None of these, however, offer the extensibility that IntenseDebate’s new plugins now offer.

Adding these plugins looks like a smart move on IntenseDebate’s part. Not only can it now tap into a pool of talented coders (and possibly hire the best ones in the long run), but – once more plugins become available – it will also be able to offer its users new features that none of its competitors offer. At the same time, this also allows the IntenseDebate team to focus on its own core product and the stability and speed of its service.
What Would You Add?
If you could write a plugin to extend your favorite commenting platform, which features would you add?