Inkscape

Inkscape is a a good software for editing/creating SVG files.

Its functionality is fundamental for as a software for drawing geometry diagrams, as it is a good middle ground between algorithmic generation, and raster graphics.

At 1.0.2, its UI is a bit terrible:

And it crashes from time to time on Ubuntu 21.04. And it has some glaring bugs, e.g.:

But still, it is a very good initiative.

What would be really amazing is if they had constraints: gitlab.com/inkscape/inbox/-/issues/1465 like proper CAD software, it would make it possible to not have to redo entire diagrams when you want to change a small part of them.

There's a tiny little crosshair that you can drag around to set the center of rotation.

And there's a button to make that crosshair snap: inkscape.org/forums/questions/can-a-pivotingtransfrom-crosshair-be-moved-and-made-to-snap-to-a-node-or-a-grid-point/#c14432

This is related to the underlying SVG pain point of SVG background color:

For PNG export: