This is a very popular blog post [1] from Jeremiah Owyang, a web strategist and analyst in SF CA.  He spends most of his time traveling from tech conference to tech summit and hobnobs with the industry leaders. 

I have been following his posts through a variety of platforms and get lots of great info from him.  Anyway, this link is about the various software apps and platforms that are termed "white label", or easily integrated into, or used as the basis of, an existing brand and website.  They include lots of social networking platforms as well as the CMS standards like Drupal, Joomla, Movable Type, Sharepoint, etc. The current PALNI website runs on a pre-packaged version of Drupal called CivicSpace.

Anyway, this is mainly just a "best of" list and a nice introduction to Jeremiah's blog.  I know several librarians who follow his work and see more and more systems and web services librarians using web strategies like he describes to improve library integration and "market penetration".