"Calibre 9.17 release brings faster ebook conversions"
"The open-source ebook editor improves output compression speeds for MOBI, AZW3 and PDB files, which makes conversions to those formats quicker. Calibre 9.17 has been released with faster ebook conversion speeds and JPEG XL image support."
https://www.omgubuntu.co.uk/2026/10/calibre-9-17-faster-conversion
OMG! UbuntuCalibre 9.17 release brings faster ebook conversions - OMG! UbuntuCalibre 9.17 has been released with faster ebook conversion speeds and JPEG XL image support. The open-source ebook editor improves output compression