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.

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.

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.

LibreCad - CAD for 2D drawing and design. Allows you to solve 2D design problems, such as preparing engineering and construction drawings, such as building plans, interior plans, machine parts or diagrams and diagrams.

KediCAD is a 2D analogue of AutoCAD.

This program has a simulation feature that allows you to make expected changes to general drawings.

KediCAD can also be used to create a drawing of the moment of inertial calculations and calculation of bends.

.

Dia is a program for creating diagrams, graphs, flowcharts, etc.
There is support for UML static structure diagrams (class diagrams), relationship diagrams, electronic elements, flow diagrams, network diagrams and many others.
Dia includes a large number of graphic elements for drawing various diagrams: block diagrams, electrical diagrams, chemistry, Cisco and others.
Diagrams are saved in XML format (additionally compressed using gzip), and export to JPEG, EPS, SVG, XFIG, WMF, PNG and other formats is also supported. You can import new objects into Dia, which are described in XML files.
Dia is extensible with new sets of objects that are described using files in an XML-based format.

Vym (View Your Mind) is a mind diagramming program. It is useful for organizing thoughts and working on structuring something.
A connection diagram (mind map, mindmap) is a color radial diagram with an image in the center, illustrating semantic and other connections between parts of scientific material.
For example, it can graphically illustrate the structure of a dissertation plan, a project plan, or the structure of government institutions in an area.
Communication diagrams have many applications in personal, family, educational, and business situations.
Opportunities include note-taking, brainstorming, summarizing, revising, and general clarification of thoughts.

Geany is a small and lightweight integrated development environment.

The basic features of Geany are:
- syntax highlighting
- code completion
- auto completion of constructs like if, for and while, XML and HTML
- call tips
- many supported filetypes like C, Java, PHP, HTML, Python, Perl, Pascal
- symbol lists
- embedded terminal emulation

An object-oriented dialect of the BASIC language, complemented by an integrated development environment and running on GNU/Linux and other UNIX-like operating systems.

It is a tool similar to Visual Basic in terms of developing Basic programs.

Gambas was conceived as an alternative for Microsoft Visual Basic developers who decided to switch to GNU/Linux

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.