I'm not saying that SunOS was somehow slow to implement these things, but that the SunOS that ran on the aforementioned SS10 shell server. Which seems about rig

I'm not saying that SunOS was somehow slow to implement these things, but that the SunOS that ran on the aforementioned SS10 shell server. Which seems about right given the fact that first Solaris with userlevel LWPs was 5.2 (dec 93) and pthread-compatibility layer was introduced in 5.5 (nov 95). And it seems quite plausible that they ran SunOS 4.x and not Solaris.