CLAM is a multiplatform software framework for research and application development for the Audio and Music domains. It offers a conceptual model for building systems as well as tools for the analysis, synthesis, and transformation of audio signals using high level representation (notes, spectral peaks, etc.). It also provides multiplatform system abstraction and tools for audio and MIDI file handling, device handling, GUI and XML support, and more. It has proper Linux audio architecture integration (Ladspa, Alsa, OSC, Jack, VST, etc.) and rapid graphical prototyping both for the processing core and the user interface (Qt designer integration).
Catalyst is a Web application framework for Perl. It is based on Maypole, and adds many features from Ruby on Rails, Struts, Spring, and Tomcat. The development philosophy focuses on Don't Repeat Yourself, Lego-like components, Code Generation, and very strong testability. It supports a number of plugins, models, views, and controllers.
Channel is a C++ template framework for distributed message passing and event dispatching. Its major components (message IDs, routing algorithms...) are highly configurable as template parameters. As a namespace shared by peer threads, channels support publish/subscribe scope control, message filtering, and translation.
Coin is an implementation of Open Inventor. Open Inventor is the de facto standard API for retained-mode 3D graphics programming. Open Inventor has a highly extensible design, and has been designed to allow for rapid development of highly interactive 3D graphics applications in the fields of CAD, engineering, scientific computing, simulation, VRML, and visualization.
CrissCross is a small cross-platform C++ library for console and file I/O, CPU identification (CPUID), hashing (MD2, MD4, MD5, SHA-1, SHA-256, SHA-512, Tiger), sockets (TCP and UDP only currently), and data structures (LList, DArray, RedBlackTree, AVLTree, SplayTree, etc). It is designed to run on Windows, Linux, FreeBSD, OpenBSD, NetBSD, Mac OS X, and even the Nintendo DS. Other platforms may become supported upon request. The main idea is to provide the ability to write a program using identical calls on the major platforms without needing to rewrite code.
Cut The Crap Software radically simplifies the task of java-based system development. Packages focussed on such problems as persistence, object model representation and XML processing contribute to the encompassing goal of viable model-based system generation from simple descriptions.
Cymbeline is an Python application server framework that includes functionality such as database and arbitrary object pooling, Web servers (including SSL), a persistent object repository, and a text console. It was originally designed as an administrative shell for an embedded system, but has since morphed into a more general purpose, run anywhere toolkit.
DEMUX Framework enables Java developers to build modular, cross-platform applications which can run on desktop, Web, and mobile and embedded devices. It is based on OSGI and supports creating JavaFX desktop applications, mobiles apps (Android, iOS, Windows), and Web applications.
DirectFB is a thin library that provides developers with hardware graphics acceleration, input device handling and abstraction, an integrated windowing system with support for translucent windows and multiple display layers on top of the Linux framebuffer device. It is a complete hardware abstraction layer with software fallbacks for every graphics operation that is not supported by the underlying hardware.