RoseThorn is a cross-platform library for 2D and 3D games running on GNU/Linux (and possibly other Unix-like OSes) and Windows. Features include: hardware accelerated 2D and 3D rendering; Ogg and WAV Sound support with OpenAL; Lua scripting; BMP, JPEG, and PNG image loading and saving (from screenshots); easily created and modified user interfaces with XML and CSS, combined with Lua event handling; separate 2D and 3D libraries; support for multiple fonts in both TTF and bitmap formats; support for OBJ, 3DS, MD5, and RTM model formats; skeletal animation (a work in progress); support for UDP and TCP networking; thread and mutex support; a Simple Shader API; 2D animated sprites; and some basic cryptography support. There is simple event management, with key/mouse bindings easily customized from the in-game console, config file, command line, or GUI.
KDE Plasma Active is a user interface for all types of tablets, smartphones, and touch computing devices, such as settop boxes, smart TVs, home automation, and in-vehicle infotainment. It is a joint project by the KDE community, basysKom, and open-slx. Its goals are a fast embedded UX platform with minimal memory requirements, customizable and modular to support different form factors, and an interface which adapts as users change activities.
Revised is a visual editor (or wizard/assistant/GUI) for Ren’Py, the visual-novel game editor. Ren'Py has a lot of capabilities, and Revised's purpose is not to allow everything that Ren'Py can do, just some of the basics. You can think of it as a step-by-step wizard to create the skeleton of a Ren'Py game.