[geeks] Oldest OS Still Developed

[Sridhar Ayengar]

Geoffrey S. Mendelson wrote:
>> 	- DOS/VE (I *think* it is still developed)

VSE is *definitely* still being developed.  I believe z/VSE 4 (the first 
64-bit version for z/Arch) is about to come out any minute now, if it 
hasn't already.

> I think it post dates OS/360 from which MVS derives, but I am not sure.
> By 1969 you had TOS (which I think was no longer supported), DOS, OS/360,
> ACP and VM/360.

VSE definitely pre-dates OS/360.  DOS was developed as a stopgap because 
OS/360 was repeatedly being delayed.  I think OS/360 finally got 
released something like 24 months after DOS.

I cut my teeth on VSE.

Peace...  Sridhar