libonion is a lightweight library to help you create webservers in C programming language. These webservers may be a web application, a means of expanding your own application to give it web functionality or even a fully featured webserver.

Cello is a GNU99 C library which brings higher level programming to C. § * Interfaces allow for structured design * Duck Typing allows for generic functions * Exceptions control error handling * Constructors/Destructors aid memory management * Syntactic Sugar increases readability * C Library means excellent performance and integration

Fast Artificial Neural Network Library is a free open source neural network library, which implements multilayer artificial neural networks in C with support for both fully connected and sparsely connected networks. Cross-platform execution in both fixed and floating point are supported. It includes a framework for easy handling of training data sets. It is easy to use, versatile, well documented, and fast. Bindings to more than 15 programming languages are available. An easy to read introduction article and a reference manual accompanies the library with examples and recommendations on how to use the library. Several graphical user interfaces are also available for the library.

Nimrod is a new statically typed, imperative programming language, that supports procedural, object oriented, functional and generic programming styles while remaining simple and efficient. A special feature that Nimrod inherited from Lisp is that Nimrod's abstract syntax tree (AST) is part of the specification - this allows a powerful macro system which allows domain specific languages. Nimrod is a compiled, garbage-collected systems programming language which has an excellent productivity/performance ratio. Nimrod's design focuses on the 3E: efficiency, expressiveness, elegance (in the order of priority).

Smisk is a simple, high-performance and scalable web service framework written in C, but controlled by Python. Smisk is currently used in production by Spotify and Livebloggen.

Cython is a language that makes writing C extensions for the Python language as easy as Python itself. Cython is based on the well-known Pyrex, but supports more cutting edge functionality and optimizations.

The Cython language is very close to the Python language, but Cython additionally supports calling C functions and declaring C types on variables and class attributes. This allows the compiler to generate very efficient C code from Cython code.

This makes Cython the ideal language for wrapping external C libraries, and for fast C modules that speed up the execution of Python code.