Interesting tools for building diagrams:
These tools take as input a text file with a description of the diagram to produce and generate an image as output.
- Graphviz [official web]: Simple but powerfull tool for graph visualization
- PlantUML [official web]: Tool to build UML diagrams, wireframes, Gantt diagrams, mind maps, ...
- Ditaa [official web]: Build general diagrams from ascii-art.
- Mermaid [official web]: Visualize graphs, sequence, Gantt, class and git diagrams.
Tools to build diagrams through drag & drop.
- Draw.io: Generalistic web tool, has an electron-based desktop version.