A collections library is one of the most important foundation services for object-oriented programming. Most object-oriented systems provide at least the start of a general-purpose collections library. The GNUSTEP, project, for example, provides the libobject library (currently in alpha test at ftp://alpha.prep.ai.mit.edu/) which includes a collections library along with other services intended to parallel those of the OpenStep framework developed by Next.

Swarm has implemented its own collection library to meet the specialized needs of its agent simulation framework.