Peruse
Peruse is a free multi-platform open source software for reading books and comics from KDE
Office software: notes, organizers, breaks, presentations, working with documents and tables.
Peruse is a free multi-platform open source software for reading books and comics from KDE
KOReader an ebook reader application supporting PDF, DjVu, EPUB, FB2 and many more formats, running on Cervantes, Kindle, Kobo, PocketBook and Android devices
Calibre is a free, open source cross-platform software for reading, converting, and organizing e-book collections
OpenComic – free and open source cross platform program for reading comics and manga
Komikku – online/offline manga reader for GNOME, developed with the aim of being used with the Librem 5 phone