I agree that it looked good at the time far as open stuff goes. I looked at it in terms of INFOSEC research. I followed all the attempts to make high-security, microkernel platforms based on it and variants. These included Trusted Mach (TMach), Distributed TMach, DTOS, and so on. That line of research led to Flask architecture, bases of SELinux. It also fed into decisions by Cambridge team to do capability-based, app sandboxing with Capsicum vs prior methods like MAC &amp; microkernels. That&#x27;s been applied to FreeBSD, CheriBSD, and Apple&#x27;s stuff.<p>So, there were lots of interesting papers and work on it. Anyone could&#x27;ve gotten sucked in. After a while, though, it became clear that Mach was a bad track with research shifting to L4 and commercial microkernels (esp RTOS, sep kernels). Torch passed to groups like Dresden and NICTA.<p>Relevant to your QNX claims:<p><a href="https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=10483544" rel="nofollow">https:&#x2F;&#x2F;news.ycombinator.com&#x2F;item?id=10483544</a><p><a href="https:&#x2F;&#x2F;web.archive.org&#x2F;web&#x2F;20011106140711&#x2F;http:&#x2F;&#x2F;www.qnx.com&#x2F;demodisk&#x2F;how.html" rel="nofollow">https:&#x2F;&#x2F;web.archive.org&#x2F;web&#x2F;20011106140711&#x2F;http:&#x2F;&#x2F;www.qnx.co...</a>