DevelKit Framework is an GNUstep/Cocoa framework with tools for reading, understanding, and generating source code from other applications. Its goal is to allow applications to generate code from non-textual representation, such as diagrams or other kinds of descriptions. Example features: an ObjectiveC source reader and generator, a project builder class, source structure related classes (class, method, and instance variables), templates, a tool for automatically generating accessor (getter ad setter), dealloc and archiving methods (interface and implementation) for a given class, and more.
Popup is an interactive learning aid for pairs of words. It behaves much like a stack of flashcards, but handles one-to-many and many-to-one word relationships better. It features an editor for cardstack files with support for copying and pasting groups of words, as well as drag and drop. It has two quizzes. One for memorization, and one for spelling practice.
NSFileHandleExt is an Objective-C extension (Cocoa/GNUstep) for the NSFileHandle class (which handles files/sockets). This extension provides support for much easier network programming for protocols like HTTP, IRC, telnet, etc. (everything that sends messages in lines suffixed by \n).
Étoilé is a GNUstep-based user environment built from the ground up on highly modular and light components with project and document orientation in mind, in order to allow users to create their own workflow by reshaping or recombining provided Services (a.k.a. Applications), Components, etc.