Steven Clarke has an excellent post about using factories in APIs . The post explains why some developers find factories difficult to use.

After posting about the Scenario Driven Design and the Design Guidelines book we are working on, I got several questions on that is "progressive API". Coincidentally I just submitted the final manuscript for a chapter that has a section on progressive APIs, so here is the related excerpt:...

The beta release of the PowerCollections library has been posted today. See http://wintellect.com/WEBLOGS/pgolde/archive/2005/06/03/1304.aspx .