The main features of ocupe/projectors are: Workflow and UI Extensions.
Open-source alternatives to ocupe/projectors include: blenderskool/kaleidoscope. bobbyanguelov/fbxformatconverter. brendanparmer/nodetopython. creativedesigner3d/prosidebar — Sidebar for Blender 2.8. danielenger/eevee-presets. axredneck/blender-md3 — .md3 models support for Blender.