[TUHS] SVR4 vs. Solaris 2

[Charles H. Sauer (he/him) via TUHS]

I assume Larry and others can be definitive about the inside Sun 
perspective on this regarding SPARC, but I hope someone can say more 
with regards to X86. I remain curious about how/why Zander et al wanted 
the Dell SVR4 team involved. Michael told me of discussions he had with 
McNealy, but I still don't see how it could have worked for either 
company. Charlie

On 11/11/2025 8:35 PM, Clem Cole via TUHS wrote:
> My memory is a bit hazy here so Tom or Larry are probably better sources
> but … IIRC they were close but not 100% identical. Remember Sparc was not a
> reference platform for SVR4 (386/486 were). The big thing Solaris lost was
> the work SunOS had done in the memory system. I never knew for sure, but I
> think that was a big reason the boot/init and the command system became
> AT&Ts version.  However some of the earlier SunOS value add was put back
> in.
> 
> For instance my memory is that Solaris could use sockets while SVR4 still
> was pushing TLI/Streams plus Solaris supported Sun Threads as well as
> pthreads while SVR4 was only pthreads. Also I don’t remember if SVR4 had
> dtrace which was a huge advantage.
> 
>   I also believe the compilers were different. As Sun had early had
> (finally) invested in their own compilers with CMU/DEC style code
> generators and optimizers; while AT&T was still using PCC2. Interestingly
> enough because Sun was charging for their new compilers suite many end
> users/customers installed the Gnu family.
> 
> Sent from a handheld expect more typos than usual
> 
> 
> On Tue, Nov 11, 2025 at 9:05 PM segaloco via TUHS <tuhs at tuhs.org> wrote:
> 
>> Pardon if this question has already been asked and answered
>> before, but I find myself curious.  System V Release 4 was a
>> joint effort between USL and Sun, which involved contributions
>> from both parties as well as other improvements.
>>
>> I often see it suggested that the first version of Solaris was
>> SVR4 itself, but my question is: Was the initial stock Solaris 2
>> release identical to USL SVR4, or were there still additional
>> value-adds that Sun made to the inaugural release of Solaris
>> beyond just the joint SVR4 trunk resulting from the project
>> between the two organizations?  In other words, when one
>> purchased and installed the initial release of Solaris, were they
>> in essence also installing SVR4 from USL, or was there some
>> appreciable difference?
>>
>> - Matt G.
>>

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