File compressors were non-free some time ago (Zip, ARJ, etc.) or at least shareware. I guess UPX executable compressor was also non-free. Other non-free catego

File compressors were non-free some time ago (Zip, ARJ, etc.) or at least shareware. I guess UPX executable compressor was also non-free. Other non-free category are media encoders/decoders (with patents behind). The other cmdline tool I remember it's non-free is tarsnap because there is a service behind.