Gmagick is a php extension to create, modify and obtain meta information of images using the GraphicsMagick API.

LibTorrent is a BitTorrent library written in C++ for *nix. It is designed to avoid redundant copying and storing of data that other clients and libraries suffer from.

Colorzero is a library for working with colors in Python. It is not intended to be as comprehensive as colormath, but is intended to be a little easier to use, particularly for beginners. The major difference with colorzero is that colors are tuples and thus immutable. Standard mathematical operators (addition, subtraction, multiplication, etc.) are used to generate new colors. Conversions are provided for a wide variety of systems including YUV, RGB565, CMYK, CIE Lab, and so on.

Library needed for GNU Go applications linked against the shared library.

YubiOTP is a library for verifying YubiKey OTP tokens. It includes both the low-level implementation for verifying tokens locally and clients for multiple versions of the Yubico validation web service. The primary audience is developers who wish to verify YubiKey tokens in their applications, presumably as part of a multi-factor authentication scheme.

pgRouting extends the PostGIS/PostgreSQL geospatial database to provide geospatial routing and other network analysis functionality.