Colt include a rather oddly-implemented ObjectArrayList. One side-effect of disconnecting the primitive type collections from their Capitalized object cousins is the leave this class somewhat out in the cold.
I would delete it, except for two things. (1) There are some speed-related APIs in here that make it potentially faster than ArrayList<T> for some purposes. (2) The hash map code uses it. For now, I've does the necessary furniture moving to preserve it, sharing a common AbstractList class with the primitive types. When I finish the array list classes, and move on to the hash maps, I may conclude that it would work just as well with a plain old ArrayList<T>, and kill the ObjectArrayList. No other code uses the ObjectArrayList in any sensible way. (There are some pointless uses of it for sorting that I've replaced with direct use of the Sorting class.)