Linux: Formerly GPL;[1] Android: GPL and commercial licenses formerly available.[2] Open-source versions are now discontinued, and it is only available under a proprietary license.
It was formerly free software under the GPL, but since 2015 (v2.7) is proprietary software.[4]
History
Nikolay Pultsin wrote the first FBReader; the tool was released for the Sharp Zaurus in January 2005, a Maemo port was added[by whom?] in December 2005 for the Nokia 770. FBReader has since had binary packages released for many mobile-device platforms and for most major personal computer operating systems.[5]
The FBReader name with the FB prefix comes from FictionBook, an e-book format popular in Russia, the country of FBReader's author.[6]
The original FBReader was written in C++; however, in 2007[7] a fork called FBReaderJ was created[by whom?], which was written in Java. As the Android platform became available in the following years, this fork became the codebase for the Android software application, while the C++ codebase remained in use for other platforms.[8]
In 2015 the software for all platforms became closed-source: the old open-source code hasn't been updated since. The Android app was split into Free and Premium versions, both closed-source, with the Premium version adding integrated support for PDF and for machine translation.[9]
Components
For easy cross-platform compiling, FBReader uses zlibrary, a cross-platform interface library. It allows recompiling for many platforms while disregarding the GUI-toolkit used.