[GEM Development] DR operating systems

[John Elliott]

> can anybody tell me something about the licence state of the Digital
> Research operating systems (CP/M, MP/M, Concurrent DOS, Multiuser DOS,
> FlexOS, Multiuser DOS, DR DOS) ?
> It`s a little bit confusing, on the one side you can download DR DOS 7
> for free, on the other side you have to pay at DRDOS.org.
> What=B4s the difference between XM/GEM and GEM/XM ?

  CP/M and MP/M are pretty much open source, though the licence is only 
granted to the Unofficial CP/M Web Site and its "maintainers, developers and 
community": <http://www.cpm.z80.de/license.html>


  The single-tasking DOS line (DRDOS) is owned by DRDOS Inc. <www.drdos.com>, 
and I think the multi-tasking line (Concurrent DOS, Multiuser DOS) ended up
with IMS <www.imsltd.com> as REAL/32. However, there was one source release 
of the DRDOS 7 kernel under a semi-open licence, and that's been developed 
as Enhanced DRDOS.

  On the borderline of the above two is DOS Plus, because it's a DOS 
product, but it's built on a CP/M kernel that's identical with Personal 
CP/M-86 v2.0.

  From what I've heard, FlexOS became IBM's 4690 Operating System 
<http://www-03.ibm.com/products/retail/products/software/4690/> and 
presumably would be sold by IBM.

  Any bits of GEM with Digital Research copyright messages are available
under the GPL, though there are some third-party drivers which I don't think
are covered by it.

  GEM/XM is a version of GEM that can multitask DOS applications, that 
forked off from GEM proper somewhere between GEM/2 and GEM/3. XM/GEM I 
haven't seen, but there were vague rumours about versions of GEM that 
ran on UNIX or OS/2 rather than DOS, and it's possible that refers to
one of them.

-- 
John Elliott