libstb is a set of single-file libraries for C/C++. The files are dual-licensed under public domain and the MIT license.

Small and dependency free Python module to infer file type and MIME type checking the magic numbers signature of a file or buffer (aka file pattern).

Beziers provides a variety of classes for constructing, manipulating and drawing Bezier curves and paths. Principally designed for font design software, it allows you to join, split, offset, and perform many other operations on paths.

Xournal++ is a hand note-taking software written in C++ with the target of flexibility, functionality and speed. Stroke recognizer and other parts are based on Xournal Code, which you can find at sourceforge. It supports Linux (e.g., Ubuntu, Debian, Arch, SUSE), macOS and Windows. Supports pen input from devices such as Wacom Tablets.

OBS plugin inspired by the built-in image slideshow, except for text sources instead. Useful for displaying song lyrics, captions, translations, etc.

The GNUstep GUI library is a powerful library of graphical user interface classes written completely in the Objective-C language; the classes are based upon the OpenStep specification, and provide the user with a traditional nextstep-like look and feel. The classes include graphical objects such as windows, menus, buttons, text fields, popup lists, browsers, scrollviews, splitviews, fonts, colors, images, events, pasteboards... You need the corresponding backend library package (gnustep-back) to use this package.