BRL-CAD is a powerful cross-platform Open Source combinatorial Constructive Solid Geometry (CSG) solid modeling system that includes interactive 3D solid geometry editing, high-performance ray-tracing support for rendering and geometric analysis, network-distributed framebuffer support, image and signal-processing tools, path-tracing and photon mapping support for realistic image synthesis, a system performance analysis benchmark suite, an embedded scripting interface, and libraries for robust high-performance geometric representation and analysis.

Scribus is an application for professional visual layout of printed documents (newspapers, magazines, brochures, literature, etc.) capable of creating high-quality pages for any purpose - be it replication for printing or electronic distribution.
Scribus supports all the features of professional publishing systems, such as extensive capabilities for layout and pre-press preparation of text, the CMYK color model, Spot Colors, the ICC color output management system, and the creation of PDF files.
This is similar to AdobeInDesign or QuarkXPress.

qCAD is a professional CAD system, similar to AutoCAD, designed for creating mechanical engineering drawings and architectural plans. You can create technical drawings such as building plans, interior plans, mechanical plans, or schematics.
You can also easily create and edit drawings with ISO templates and save files in DXF format. The DXF format is used by many CAD systems.

A simple drawing program for young children from 3 to 12 years old (eg kindergarten and primary school).
It is not an ordinary drawing tool. It's simple and fun to use. Sound effects and the animated nature of the program will help the user understand what is happening on the screen and will try to cheer him up.
You can draw using brushes or make shaped prints using stamps. For example, a teacher can make several animal figures and ask the children to draw the surrounding space in which they live.
Each shape has a melody and text prompts that are played and displayed when the child selects a shape.

Blender is a complex 3D modeling, animation, rendering, post-processing, interactive creation and playback (games).
With its help, static pictures, animation, models for games, as well as interactive information content in the form of independent programs are created.
It is possible to automate the program using Python scripts. In particular, import and export to popular file formats, such as 3D Studio and Wavefront Obj, are implemented in the form of scripts.

GIMP (a direct alternative to Adobe Photoshop) is a raster graphics editor, an alternative to Adobe Photoshop) for creating and processing raster graphics and partial support for working with vector graphics.

The editor supports more than thirty image formats and can work with layers, masks, filters and blending modes. The program has a huge range of tools for color correction and processing of any photographs and images.

Thanks to the user-friendly interface and nice features, learning to work in the editor is very easy.

Pinta is an easy-to-use graphics editor. Its goal is to provide a simple and convenient experience for ordinary users.

Some of the supported features:
- image adjustment (automatic level correction, black and white image, sepia, ...)
- effects (motion blur, glow, warp, ...)
- working with layers
- unlimited depth of undo/redo actions
- drawing tools (brush, pencil, shapes, ...)

Designed for creating full-fledged animated films. Allows you to avoid creating intermediate frames, eliminating the need to manually draw each frame.

Colobot (Colonize with Bots) is a game aimed at teaching programming through fun. You play the role of an astronaut traveling with robot assistants in search of a planet to colonize.
The game features real-time 3D graphics and the C++ and Java-like object-oriented language CBOT, which can be used to program the robots available in the game.

Lazarus is an integrated cross-platform software development environment in a Delphi-like environment in the Object Pascal language for the Free Pascal Compiler (often abbreviated FPC).
It is currently the only Rapid Application Development (RAD) tool that allows Delphi programmers to create GUI applications for Linux (and other non-Windows) systems.
Allows you to easily transfer Delphi programs with a graphical interface to various operating systems: Linux, FreeBSD, Mac OS X, Microsoft Windows, Android.