The EDCommon framework provides seamless extensions of Foundation and AppKit. The EDStyleSheet and EDMessage frameworks provide services for Internet applications, style sheet driven export of your objects and message handling.
The MulleEOInterface framework is a binary replacement for the EOInterface framework that Apple delivered in their Objective-C version of WebObjects (4.5). It's the link between EOControl and AppKit. Also features MulleEOObserver.
Mulle XMLRPC is a client/server implementation of the XML-RPC specification. It consists of a bunch of classes involved in managing the protocol aspects such as XML parsing/creating and transporting. As a user of the framework, you usually get in touch with a few classes and two Objective-C protocols only.
OCMock is an Objective-C implementation of mock objects. It creates mock objects on the fly and uses the trampoline pattern so that you can define expectations and stubs using the same syntax that you use to call methods.
iTunesFS allows you to mount the iTunes database and all your local iPods as a file
system, using the excellent MacFUSE.
Albums, Artists and all Playlists are exposed as directories, with their respective entries, allowing for painless backups.