they may have updated the website since the numerous comments here but the about section acknowledges all the libraries they use
Libraries
A big thanks to FFmpeg (audio, video), libvips (images) and Pandoc (documents) for maintaining such excellent libraries for so many years. VERT relies on them to provide you with your conversions.
Libraries
A big thanks to FFmpeg (audio, video), libvips (images) and Pandoc (documents) for maintaining such excellent libraries for so many years. VERT relies on them to provide you with your conversions.