After five and a half years of development took the release of the project Rockbox 4.0, developing alternative firmware for various models of audio players. Compared to standard firmware, Rockbox provides support for additional formats, functions, and plugins. The project is not based on Linux and comes with its own POSIX-compatible core. The code is written in the language of C and is distributed under the GPL license. Rockbox can be loaded from a memory card without removing the main firmware of the player.
Among available in Rockbox functions: an alarm clock, viewing documents, photos and videos, voice interface, support for song texts and album covers, a system of bookmarks, a dictaphone, recording with FM Radio, and a simple file manager. Differences also noted include energy efficiency (19-21 hours instead of 14-16 hours) and high speed when working with large playlists. Rockbox supports up to 20 thousand compositions in the playlist and up to 10 thousand files in directories, whereas the Archos firmware supports no more than 999 files.
- Added devices:
- AIGO EROS Q, EROS K, and models such as Agptek H3, Hifiwalker H2, and Surfans F20.
- Fiio M3K.
- Shanling Q1.
- XDUOO X3II and X20.
- Ports for devices:
- are translated into the stable category.
- Agptek Rocker.