Werner Losh: However, the complicating factor here is, I think, that SYS V uses a lot of code from the later editions of Unix, so relicensing the newer research versions might cut into the license streams from them in some way. At least that was reported at the time of the only through 7th edition licensing. ======= I'm not sure who would have reported that `System V uses a lot of code from [post-7th] editions of UNIX.' I may be misled by having had my hands and eyes mainly on the kernel and the most-basic commands like the shell, but offhand I can't think of any System V code at all that was adopted directly from the Research systems in the 8th, 9th, or 10th Edition eras. There were certainly ideas that were picked up, mulled over, and re-implemented in changed form by the System V people, sometimes better and sometimes worse than the original; but not straight code transplants. The systems had diverged far too much for that to be easy. If anything, the licensing problem runs the other way: System V code taken in by the Research system. For example, the C compiler we used most was based on pcc2, developed on the System V side of the company after Steve Johnson moved there. I think our version of make may have been based on a System V version as well. I'm sure there are other (mainly smaller) examples, though since we used no source-code control mechanism, tracing the details is non-trivial. None of which invalidates the basic point: there's certainly plenty of entanglement, whether because 10/e includes ideas that were used commercially in System V and whose mutant descendants are still present in Solaris, or because 10/e includes some source code directly descended from System V. It's a shame we didn't get the several companies whose lawyers might care to agree that there's nothing of commercial value in the latter-day Research systems back when it was simpler to figure out who those companies were. As I've reported here before, there was actually some thought by certain persons here (and one who is, alas, no longer able to be here) of doing that, some years back, but a certain irksome legal circus about UNIX IP got going too quickly for that to happen, and left us with the confused situation we have today. Norman Wilson Toronto ON