OS/2 started out as a joint venture between MS and IBM. So MS was not stealing from OS/2 but rather provided a lot of technology from the start in the late eighties.
I used OS/2 Warp 3 daily on my private machine back from 1995-1996. It was a nice OS with some innovative features:
- It came with HPFS (high performance file system) that worked nicely with large hard disks (I personally used it on a 540 MB drive I could afford back then.) and, more importantly, support long file names and extended file attributes which you could use to store sophisticated meta information inside. However, it was not doing any kind of journalling so would still be prone to file corruptions similar to ext2.
- It used preemptive multitasking that worked rather well even back on my DX4/100 MHz. You could play videos in the background and work on a text document without problems. You could even run multiple virtualized DOS games in little windoes next to each other on a single core CPU -- they would work but would, of course, drop some frames. However, there was this infamous design flaw of using a "Synchronous Input Queue" inside the "presentation manager" sending UI events to programs that (when they stopped servicing those) could still bring down all of the UI.
- It came with the "enhanced text editor" leveraging 32-bits to support editing large files and was extensible to a point you could use for software developing. Although, back then, I did not do much of that as a teenager. I rather ran Visual Basic 3.0 on OS/2 to did simple GUI programs.
- It came with WINOS2 being a full native windows 3.1 runtime so you could run windows apps seamlessly on your OS/2 desktop. If you had enough memory you could run a separate Windows core for each application and, this way, get a much more stable execution environment for Windows programs. IBM had full rights to use, ship and modify 16-bit Windows to keep it compatible with OS/2. That, of course, would not fly starting with WIN95.
- It used 386's "virtual real mode" to run full DOS environments for DOS programs. It had nice GUI support for allowing you to tweak DOS settings for each program separately to get as much conventional memory as you wanted for it. Even DOOM ran nice inside of OS/2 (but did not support Sound Blaster sound).
- The desktop supported the notion of "templates" you could create documents from. So, basically, you would not need to open an application to create documents but just dragged a new file from a template icon enabling "document centric" work flows. Or you could drag a file directly to the printer icon.
- IBM even provided a web browser for free on OS/2's bonus disk -- "Web Explorer". That worked actually quite well in the beginning. Later I switched to Netscape Navigator in its OS/2 version.
- OS/2 Warp 4 shipped with a speech recognition system for controlling the shell and even dictate text. That was seriously cool back then!
