Free computer libraries

Haml (HTML Abstraction Markup Language) is a templating system that is designed to avoid writing inline code in a web document and make the HTML cleaner. Similar to other template systems like eRuby, Haml also embeds some code that gets executed during runtime and generates HTML code in order to provide some dynamic content. In order to run Haml code, files need to have a extension. These files are similar to .erb or .eRuby files, which also help embed Ruby code while developing a web application.

programming language

MonoGame is a free and open source C# framework used by game developers to make games for multiple platforms and other systems. It is also used to make Windows and Windows Phone games run on other systems. It supports iOS, iPadOS, Android, macOS, Linux, PlayStation 4, PlayStation 5, PlayStation Vita, Xbox One, Xbox Series X/S and Nintendo Switch. It implements the Microsoft XNA 4 application programming interface (API). It has been used in several notable games, including Bastion, Celeste, Barotrauma, Fez, and Stardew Valley.

U++, formally known as Ultimate++ - is a C++ RAD framework that aims to reduce the code complexity of typical desktop applications by including all necessary toolkits into a single C++ framework. Programs created with U++ work on multiple Operating Systems and Hardware Architectures with performance without needing to write platform-specific code.

Zopfli is a data compression library that performs deflate, gzip and zlib data encoding. It achieves higher compression ratios than mainstream Deflate and zlib implementations at the cost of being slower. Google first released Zopfli in February 2013 under the terms of Apache License 2.0. Google archived the project in October 2025.

Embedded Ruby (also shortened as ERB) is a templating system that embeds Ruby into a text document. It is often used to embed Ruby code in an HTML document, similar to ASP and JSP, and PHP and other server-side scripting languages. The templating system of eRuby combines Ruby code and plain text to provide flow control and variable substitution, thus making the combined code easier to maintain.

Newlib is a C standard library implementation intended for use on embedded systems. It is a conglomeration of several library parts, all under free software licenses that make them easily usable on embedded products.

thumb|upright=1.5|The Linux API is composed out of the System Call Interface of the Linux kernel, the [[GNU C Library, libcgroup, libdrm, libalsa and libevdev (by freedesktop.org).]]

fast data compression and decompression library written in C++ by Google

human language processing system

computer software for electronics prototyping

libuv is a multi-platform C library that provides support for asynchronous I/O based on event loops. It supports epoll(4), kqueue(2), Windows IOCP, Solaris event ports and Linux io_uring. It is primarily designed for use in Node.js but is also used by other software projects. It was originally an abstraction around libev or Windows IOCP, as libev does not support IOCP. In node-v0.9.0's version of libuv, the dependency on libev was removed.

MicroG (typically styled as microG) is a free and open-source implementation of proprietary Google libraries that serves as a replacement for Google Play Services on the Android operating system. It is maintained by the German developer Marvin Wißfeld. He describes microG as "the framework (libraries, services, patches) to create a fully-compatible Android distribution without any proprietary Google components".

LessTif is a defunct free software reimplementation or clone of the Motif computer programming toolkit. The project aimed for full source- and binary-code compatibility with Motif. While this was not achieved, many Motif applications could run with LessTif or be compiled with it.

Eclipse Vert.x is a polyglot event-driven application framework that runs on the Java virtual machine.

Merb is a discontinued model–view–controller web framework in Ruby, notable as a precursor to Rails 3. It brought increased focus on speed and modularity to Rails 3. The name Merb is a contraction of "Mongrel" and "Erb".

The Computational Geometry Algorithms Library (CGAL) is an open source software library of computational geometry algorithms. While primarily written in C++, Scilab bindings and bindings generated with SWIG (supporting Python and Java for now) are also available.

style sheet language

template system for web pages

widget toolkit for the X Window System

SVGAlib, styled as "Linux SuperVGA Graphics Library", is a legacy open-source low-level graphics library for accessing SuperVGA hardware on PC-compatible systems running on Linux, with later ports to AmigaOS and FreeBSD. SVGAlib allowed programs to change video mode to display full-screen graphics, without the use of a windowing system. Alongside X11 and the General Graphics Interface, it was one of the earliest libraries allowing graphical video games on Linux.

llama.cpp is an open source software library that performs inference on various large language models such as Llama. It is co-developed alongside the project, a general-purpose tensor library.

openFrameworks is an open-source toolkit designed for creative coding founded by Zachary Lieberman, Theo Watson and Arturo Castro. OpenFrameworks is written in C++ and built on top of OpenGL. It runs on Microsoft Windows, macOS, Linux, iOS, Android and Emscripten. It is maintained by its founders with contributions by other members of the openFrameworks community.

GNU plotutils is a set of free software command-line tools and software libraries for generating 2D plot graphics based on data sets. It is used in projects such as PSPP and UMLgraph, and in many areas of academic research, and is included in many Linux distributions such as Debian. Windows and Mac OS X versions are also available. The library provides bindings for the C and C++ languages. Its stand-alone command-line tools can generate graphs and perform numerical calculation of spline curves and systems of ordinary differential equations. Plotutils is a GNU package and is distributed under a

an object file library used by the GNU debugger, assembler, linker, and the binary utilities

Open-source, cross-platform toolkit for N-dimensional scientific image processing, segmentation, and registration.

In computing, klibc is a minimalistic subset of the standard C library developed by H. Peter Anvin. It was developed mainly to be used during the Linux startup process, and it is part of the early user space, i.e. components used during kernel startup, but which do not run in kernel mode. These components do not have access to the standard library (usually glibc or musl) used by normal userspace programs.

QtScript is a scripting engine that has been part of the Qt cross-platform application framework since version 4.3.0. It was first deprecated as of Qt 5.5, then dropped as of Qt 6.5, and replaced by Qt Meta-object Language (QML).

ThreadWeaver is a system library initially developed for KDE Software Compilation 4 and later refactored for KDE Frameworks 5.

JUCE is an open-source cross-platform C++ application framework, used for the development of desktop and mobile applications. JUCE is used in particular for its GUI and plug-ins libraries. It is dual licensed under the AGPLv3 and a commercial license.

LZFSE (Lempel–Ziv Finite State Entropy) is an open source lossless data compression algorithm created by Apple Inc. It was released with a simpler algorithm called LZVN.