pyRevit

pyRevit turns Autodesk Revit into something you can automate without a software team. Revit is the heavyweight CAD tool architects and engineers model buildings in, and out of the box, repetitive tasks eat hours. pyRevit lets you write small scripts in Python and drop them into the Revit toolbar as buttons your whole office can click. Free, open source, GPL licensed.

Setup is an installer, not a DevOps project, which is the point. You sketch an idea, wire it to a button, and push it to the team through one shared interface. It ships with a pile of built-in tools so you're not starting from zero, and there's a CLI and a telemetry server if you want to manage deployment and usage across a larger firm. The scripting is IronPython or CPython, approachable for someone who isn't a career programmer.

This is for the person inside an architecture or engineering shop who got tired of doing the same Revit chore fifty times and wants to fix it. Solo practitioners get the built-in tools for free. Firms get a way to standardize workflows without paying a vendor to build custom add-ins. There's no paid tier, it's free at every size.

The catch is the blast radius is exactly one application. If your team doesn't live in Revit, none of this matters. And GPL means anything you distribute on top inherits the license, so check that before you ship custom tools outside your own walls.