V.E.R.A. -- Virtual Entity of Relevant Acronyms (September 2014):
Operating System /2 (IBM, OS), "OS/2"
The Jargon File (version 4.4.7, 29 Dec 2003):
/O S too/, n.
The anointed successor to MS-DOS for Intel 286- and 386-based micros; proof
that IBM/Microsoft couldn't get it right the second time, either. Often
called ?Half-an-OS?. Mentioning it is usually good for a cheap laugh among
hackers ? the design was so baroque, and the implementation of 1.x so
bad, that three years after introduction you could still count the major
apps shipping for it on the fingers of two hands ? in unary. The 2.x
versions were said to have improved somewhat, and informed hackers rated
them superior to Microsoft Windows (an endorsement which, however, could
easily be construed as damning with faint praise). In the mid-1990s IBM put
OS/2 on life support, refraining from killing it outright purely for
internal political reasons; by 1999 the success of Linux had effectively
ended any possibility of a renaissance. See monstrosity, cretinous,
The Free On-line Dictionary of Computing (18 March 2015):
/O S too/ IBM and Microsoft's successor to the MS-DOS
operating system for Intel 80286 and Intel 80386-based
microprocessors. It is proof that they couldn't get it
right the second time either. Often called "Half-an-OS". The
design was so baroque, and the implementation of 1.x so bad,
that 3 years after introduction you could still count the
major application programs shipping for it on the fingers of
two hands, in unary. Later versions improved somewhat, and
informed hackers now rate them superior to Microsoft
Windows, which isn't saying much. See second-system
On an Intel 80386 or better, OS/2 can multitask between
existing MS-DOS applications. OS/2 is strong on
connectivity and the provision of robust virtual machines.
It can support Microsoft Windows programs in addition to its
own native applications. It also supports the Presentation
Manager graphical user interface.
OS/2 supports hybrid multiprocessing (HMP), which provides
some elements of symmetric multiprocessing (SMP), using
add-on IBM software called MP/2. OS/2 SMP was planned for
release in late 1993.
After OS/2 1.x the IBM and Microsoft partnership split.
IBM continued to develop OS/2 2.0, while Microsoft developed
what was originally intended to be OS/2 3.0 into Windows NT.
In October 1994, IBM released version OS/2 3.0 (known as
"Warp") but it is only distantly related to Windows NT.
This version raised the limit on RAM from 16MB to 1GB (like
IBM introduced networking with "OS/2 Warp Connect", the first
multi-user version. OS/2 Warp 4.0 ("Merlin") is a network