Ipe
The Ipe extensible drawing editor
...Users can draw geometric shapes, paths, curves, and text with accurate alignment and positioning. The software integrates LaTeX typesetting, allowing mathematical expressions and document macros to appear directly within illustrations. Its snapping tools simplify geometric constructions and object alignment. Ipe also supports multilayer drawings, reusable styles, and extensions called ipelets. Available for Windows, macOS, Linux, and web browsers, it provides researchers, educators, and technical authors with a flexible environment for producing publication-quality vector graphics.