Coldfusion Bundled with Jakarta Commons Collection
I was requiring a synchronized First in First Out (FIFO) Queue, to store some CFCs for reuse, and I was doing some digging around to see if there was anything already implemented, or if my best bet was to go for just using a synchronized linked list for the Java Collections Framework.
So I did some reasearch, and asked on AJUG, and came across the Jakarta Commons Collection library.
I already knew that ColdFusion had quite a few org.apache libs sitting underneath it (xalan, log4j, axis etc), so I figured I would do some checking and see if the Collections where also there, and strangely enough, they were!
There is a whole lot of very useful collections in here, including Bags, Buffers, MultiMaps, PriorityQueues... all sorts of stuff.
So if you are looking for a collection that you can't seem to find in the regular ol' Java, I suggest checking out the Commons Collection - you should be able to find what you are looking for.