Alfresco and Facebook
Many open source software projects have started to experiment with Facebook to facilitate social networking within their community. Alfresco has taken things to another level by building an integration with Facebook to surface the Alfresco repository in a Facebook application. I think this ties nicely with the concept of using Facebook for the social networking aspect of your Intranet.
This integration uses Alfresco's Web Scripts feature that allows you to create your own server side API (written in Javascript) for things like AJAX-style interactivity. I think of Alfresco's philosophy as "enlightened ECM." Rather than try to build everything on their own platform (and find yourself managing a collection of second rate applications), Alfresco's strategy is to integrate with best of breed applications. You look at their website and they use MediaWiki for their wiki, WordPress for blogs, and Baynote for search. All the open standards and APIs give you great tools to do these integrations. I used to think of this as Alfresco talking the ECM talk but not walking the walk. Now I get that they see the old ECM vision as being as outdated as I do.
Of course, this strategy has its liabilities. The integration requires development work and the result doesn't always function smoothly (try searching for something on the Alfresco and you will see what I mean). Some customers just want everything out of the box (even if the features are lame and never get used) and don't want to be bothered with best of breed if it requires expensive and risky integration. However, I think it is safe to say that most current Alfresco customers (who were attracted to the product because of its architecture and standards support) like the idea of integration and service based architectures.