LAN Manager might have hacked something over the top, but OS/2 was fundamentally a single-user OS, no different to DOS or MacOS.
My understanding is that NT had quite a bit of OS/2 in it.
It doesn't. They are completely different architecturally. NT was a 32-bit, multiuser, heavily multithreaded, built-for-SMP, portable, mostly-microkernel OS.
OS/2 was... Not.
Seeing that MS had rights to OS/2 and wanted a new OS in a hurry following the breakdown of their partnership with IBM, it would be suprising if they had not used parts of OS/2.
In a hurry ? It was five years between the start of NT's development ('88) and its first release ('93).
Seriously, the 8088/80286 and their addressing space limitations set back the DOS-based world by years, until Intel finally accepted that people wanted to use individual chunks of memory larger than 64K, and that they wanted to run their old real-mode DOS programs, too.
Intel wasn't the problem. The 386 was released in 1985.
Win 3.0 was absolutely awful. It crashed and needed a reboot about twice an hour.
It was soon replaced with the improved 3.1.
It was two years between Windows 3.0 and 3.1.
One major reason for the split was that IBM insisted on programming OS/2 in assembler - over Gates' objections - locking them onto the 386 platform.
At least that is the way I remember it.
I think you are remembering IBM's insistence that OS/2 ran on their shiny new "AT", with it's 286 processor when the 386 was already out on the market.
It was already working on the next version of OS/2, but split from IBM's path and re-branded the new product as Windows NT. IBM then started their own separate development path and produced OS/2 2.0.
Minor correction. Microsoft - Dave Cutler's team - were working on the OS that was going to replace OS/2 (OS/2 "New Technology") that was then turned into Windows NT 3.1 and successors after the (surprising) Windows 3.0 success.
IBM took the "old" OS/2 code (that both they and Microsoft had worked on) and tarted it up into OS/2 2.x and successors.
Windows NT and OS/2 have no common ancestor. They are completely different OSes from bottom to top.
That explains why in the mid '80s to mid 90's IBM was busy in a joint venture with Microsoft first and alone afterwards... to produce a PC system with networking, multi-tasking and file permissions and even 32 bits (OS/2).
OS/2 (at least in that timeframe) was not multiuser. Neither was it 32-bit (IBM insisted it run on their brand-spanking new AT with its 16-bit 286 CPU).
And the Microsoft/IBM "divorce" was around 1990.
With that said I don't agree with GP. I don't think IBM had that much strategy.
Win 3.x would pre-emptively multitask DOS windows if you had a 386. It was one of its touted features. (There may have been a setting to turn this off and on, it may have been off by default). Personally during this period I used DESQview (or however it was capitalized) as a multitasker.
Windows 3.0/3.1 would pre-emptively multitask DOS windows if running on an 80386.
So did the Acorn Archimedes (the computer the ARM CPU was originally made for). RiscOS even had things like anti-aliased fonts by then, and certain user interface concepts that didn't show up elsewhere until Mac OSX came out.
However, the PC and Microsoft was already massively entrenched, and the news was huge - finally the computers most people actually used at work were going to catch up with the Mac, Amiga, Archimedes and other machines.
But anyone could tell that Windows was going to be huge. The PC was already dominant and Microsoft was already nearing monopoly position in the PC market (and IBM compatibles at the time had fallen in price such that they were price competitive with the Amiga) and the upgrade path for most people was not to buy a whole new computer but just add Windows.
I remember the news at the time. It was huge. Finally, the PC that nearly everyone was using was catching up to the Mac, Archimedes, Amiga etc.
Is there actually a way for US businesses to prevent themselves from hostile takeover? Like, can they be "private limited companies" and just refuse to merge? If so, I think these guys should tell EA to fuck off, on principle.
Speak for yourself, I was never part of such a consensus. We had a nice slow evolution of user interfaces going on and they came in and fucked everything up.
That overly buttery stuff that's so rich it makes me want to throw up from a mile away? Eww.
I prefer their nice pizza sauce.
Believe it or not some of us like the fatty cheesy goodness on Pizza Hut pizzas, and as for meat feast, ohh baby.
I can take or leave "authentic" Italian wafer-thin crispy bases with virtually no cheese and often uncooked ingredients. Overrated.