@patrick_h_lauke @rysiek Darktable can iirc, you just need to ask Lightroom to create sidecar files and work with those, not just the single catalog file, doesn't seem that difficult.
@darktable themselves might have some rough idea on where to point you for that
@tek_dmn @rysiek @darktable but likely that only loads general exposure settings and metadata, any actual edits would not carry over?