I started off in the world of maps. That world is lucky enough to have a thing called GDAL: a big community effort around a parser, generator, and converter for all the geospatial formats. It's not totally exhaustive but it's pretty close! Some domains have this thing and others don't. This is a list of those things.
I'm trying to just name one per domain - this isn't an exhaustive list of all the converts. Just trying to highlight the one ultra-converter: if it exists!
- Geospatial, maps, spatial data: GDAL
- Text documents: Pandoc
- Images: GraphicksMagic
convert
- Audio: XLD for lossless audio
- Video: ffmpeg
- 3D CAD Formats
- Tabular data
- Geneaology formats
- JSON/YAML and other structured data