MUSCLE (Multi User Server Client Linking Environment) is an N-way messaging server and networking API. It includes client-side networking APIs for various languages, including C, C++, C#, Delphi, Java, and Python. MUSCLE lets programs communicate over a network via streams of serialized Message objects. The included server program ("muscled") lets its clients message each other and store information in its server-side hierarchical database. The database supports flexible queries via hierarchical wildcarding, and "live" updates via a subscription mechanism.
Archetypes is a framework for developing new content types in Plone. The power of Archetypes is first in automatically generating forms, second in providing a library of stock field types, form widgets, and field validators, third in easily integrating custom fields, widgets, and validators, and fourth in automating transformations of rich content.
The PEAK library tries to achieve high performance in combining multi-threading with an efficient I/O event model. You can write event-based applications that use massive sockets I/O, timers, and signals. Its underlying I/O multiplexing engine supports kqueue(2) (FreeBSD, NetBSD, and Mac OS X), epoll(2) (Linux 2.6), and /dev/poll (Solaris). It provides support for optimized memory allocations, basic database primitives, and synchronization.
Elektra is a universal hierarchical configuration store, similar to GConf and the Windows Registry. It allows programs to read and save their configurations with a consistent API, and allows them to be aware of other applications' configurations, leveraging easy application integration. While architecturally similar to other OS registries, Elektra does not have most of the problems found in those implementations. Elektra includes a library, an API, and commandline and GUI tools for administration tasks.
UnCommon Web is a Web application framework. UnCommon Web features a component based UI construction toolkit, template and programmatic dynamic HTML generation engines, and linear (also known as modal or continuation) page flow control. UnCommon Web can sit behind Apache or a pure Lisp Web server.