V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

BEOS
       Be Operating System (OS), "BeOS"


The Free On-line Dictionary of Computing (30 December 2018):

BeOS

    The operating system originally designed
   to run on the BeBox microcomputer.  BeOS is good at both
   multitasking and real-time operation.  It has a bash
   command shell, with ports of many GNU programs by Be, Inc.
   It has a GUI front end (not X).  A C++ compiler is
   supplied with the machine, and there are rumours of other
   languages being ported in the future.

   BeOs eventually became used on the x86 and
   standard PPC.

   Be, Inc. went bankrupt in 1999, after releasing the last
   upgrade of BeOS (R5.0.3), and was sold to Palm.

   Several groups are currently (2003) attempting to create an R6
   version of the OS.  The most likely to succeed are Yellowtab
   and OpenBeOS, which is likely to be renamed.

   (2003-05-30)