The POSIX subsystem was one of the worst offenders for the &quot;checkbox marketing&quot; abuse that I&#x27;ve ever seen.  I am hard pressed to think of anybody who successfully used it for anything because it came with so many caveats right out of the box.  Microsoft implemented the absolute minimum they needed to check the box and nothing more.<p>I don&#x27;t know about the OS&#x2F;2 subsystem, but I wouldn&#x27;t be surprised if it was only sufficient to run Lotus Notes or something back when that was a relevant business need.