[Info-vax] Reimplementing VMS, was: Re: HP adds OpenVMS Mature Product Support beyond the end of Standard Support

[Stephen Hoffman]

On 2014-02-04 16:55:05 +0000, JohnF said:

> Stephen Hoffman <seaohveh at hoffmanlabs.invalid> wrote:
>> On 2014-02-04 14:48:20 +0000, JohnF said:
>>> Thanks. P.S. Got any free ones?
>> haha that's just so cute.
> 
> Why? There are quite a few enormous projects available for free.   Of 
> course, the demand for a "vms api" is probably insufficient to attract 
> any serious gpl development effort.

Why?

Have at, then.

Most folks getting into this area of development are seeking to recoup 
the costs of the effort.

Sure, there are some ginormous free packages around, but those usually 
"scratch an itch" that more than a few folks share.

For OpenVMS?   Demand for that is low, the effort involved in even a 
small emulation is high — we're right back to discussing and dealing 
with some fraction of the 25+ million lines of code present in OpenVMS 
that's involved in any rewrite-port project that's been discussed, and 
that's before the layered products are in play, and the API code 
coverage (overlap) and the OS-dependencies among different and disjoint 
applications is low.  Then toss in dealing with dependencies on Oracle 
Rdb or some other third-party product.  For somebody that's doing this 
sort of compatibility stuff locally and privately, it's also becomes 
the choice of just rolling the changes directly into the source code, 
as compared with trying to keep the source code API-compatible with the 
OpenVMS API designs.

I do know of some folks that do source-to-source translations using 
their own tools, but AFAIK they don't handle RTL or system service 
calls or related VMS baggage.

Or put another way, if there were a cheap or free way to migrate, HP 
would be pointing folks at it.   If you find a freebie with more than a 
little coverage, post it.   Or if you want to invest in creating 
something of the scale of one of these platform emulations and then 
give it away, well, maybe have a look at helping the FreeVMS folks?  
But expecting to find free porting tools?  Um, OK.  Good luck with that.


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