Non-BeOS Implementations
The majority of the Be API has been reimplemented by Haiku for their opensource BeOS replacement, although in an effort to catch up with the intervening years since BeOS R5 some additional functionality has been added, ranging from large changes to the Mail kit to support IMAP, encrypted connections and multiple accounts, and a move to OpenGL 1.5 support via Mesa 3D.
Alternative systems have attempted to draw some inspiration (Syllable) from the BeOS API, but are not making attempts to provide a base to port applications.
A private port of much of the API to Microsoft Windows and later Linux (using GTK+) was done by Gobe Software to enable them to port their Gobe Productive office suite to these platforms from BeOS, where it had originally been developed.
Read more about this topic: Be OS API