Read/Write Web has a good overview of Elgg Learning landscape and an interview with Dave and Ben, the co-founders. [I had mentioned that I believe that Elgg is one of the few online learning systems that is not affected by the current Blackboard LMS patent suit, though there are other Blackboard patents that may be a cause for concern].
The overview is a brief look at what Elgg currently offers and what is coming soon, including Elgg Spaces. This article is excellent for anyone unfamilar with Elgg, as Read/Write Web is not about educational technology, so they don’t assume that the reader knows everything about the field.
