QWebSockets is a pure Qt implementation of WebSockets, both client and server. It is implemented as a Qt source code module (.pri file) which can easily be embedded into existing Qt projects. It has no dependencies other than Qt. It features text and binary sockets, frame-based and message-based signals, proxy support, and strict Unicode checking.
STMX is a high-performance Common Lisp library for composable Transactional Memory (TM), a concurrency control mechanism aimed at making concurrent programming easier to write and understand. Instead of traditional lock-based programming, one programs with atomic memory transactions: if a memory transaction returns normally it is committed. If it signals an error, it is rolled back. Transactions can safely run in parallel in different threads, are re-executed from the beginning in case of conflicts or if consistent reads cannot be guaranteed, and effects of a transaction are not visible from other threads until committed. This gives freedom from deadlocks, automatic rollback on failure, and aims to resolve the tension between granularity and concurrency.
ENet for C# wraps the C-language ENet networking library. For games and other realtime applications, if you use TCP, old data can hold up newer data, even if it is no longer relevant (old positions, etc.). Your players will perceive any lost packet as a "lag burst". ENet supports multiple in-order streams of data, and allows you to decide on reliability on a per-packet basis. The library is useful for both client-server and peer-to-peer architectures.
exceptions4c is a tiny, portable framework that brings the power of exceptions to your C applications. It provides a simple set of keywords (macros, actually) which map the semantics of exception handling you're probably already used to: try, catch, finally, throw. You can write try/catch/finally blocks just as if you were coding in Java. This way you will never have to deal again with boring error codes, or check return values every time you call a function.
SHTns is a high-performance Spherical Harmonic Transform library. It was designed for numerical simulation (fluid flows, mhd, etc.) in spherical geometries, but can be used for any kind of problem involving scalar or vector spherical harmonics. It is very fast, thanks to careful vectorization and runtime tuning. It supports multi-threaded transforms via OpenMP. It features scalar and vector transforms, synthesis and analysis, and flexible truncation and normalization. A Python interface is included.
jPDFImages is a Java library to export images from PDF files and import images into PDF files. It can create images from pages in a PDF document and export them as JPEG, TIFF, or PNG images. It can return the image of any page in the document to the host Java application as a BufferedImage for further processing or to save in different formats. It can create documents or add pages to existing documents by importing TIFF, JPEG, and PNG images. After creating or modifying a document, it can save to the local filesystem or to an output stream to be able to serve the document directly to a client browser when working within a J2EE server. jPDFImages is built on top of Qoppa's proprietary PDF technology, so you do not have to install any third party software or drivers. It is also 100% Java, so it is completely platform-independent.