MyGUI is a GUI library which aims to be fast, flexible and simple GUIs in C++. Features include Layout Editor. Multicolour text. Per pixel cut. Changing alpha support for widgets (also in states configuration). Interface localisation. Fast RTTI for safe casts. Tool tips. Animated cursors and pictures. User xml resources. Truetype fonts and fonts from texture. Widgets controllers (moving, fading and so on). Flexible configuration in xml config file. Subskins with tiling, with direct access to texture. Possibility to store any data in widgets items. Skin themes. Wrappers for fast UI development. Drag'n'drop.

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.