KOReader is a versatile document viewer designed for e-ink readers, available on various devices and operating systems. It offers support for multiple document formats, customizable reading settings, and integration with popular content providers. KOReader is optimized for e-ink devices with a fast page-turning speed and a range of additional features like dictionary look-up and over-the-air updates. Developed and supported by volunteers worldwide, users can contribute by fixing bugs, translating the program, or sharing knowledge on the forum. KOReader is continually evolving, so check the user guide and wiki for more features and ways to get involved.
https://github.com/koreader/koreader