[bo1024]

- I appreciate these posts that promote software freedom.

- The tools `convert` and `ffmpeg` should cover your criteria and the functionality of the site.

[knight17]

Thank you for suggesting this. I never knew about this. I learnt that it is from/ part of Imagemagick [1].

Unoconv tool [2], recommended in another comment here, is also great to convert documents to and from formats that are supported by OpenOffice (LibreOffice?).

Pandoc [3] is also a worthy option to convert between document formats.

[1] : https://www.imagemagick.org/script/convert.php, https://www.lifewire.com/convert-linux-command-unix-command-...

[2] : http://dag.wiee.rs/home-made/unoconv/

[3] : http://pandoc.org/

[systoll]

unoconv too, for the office formats.

[bo1024]

Thanks