Not organized to be able to just throw out a reference and many disappeared over time as old web faded. It&#x27;s more something you see relative to other OS&#x27;s than an absolute. I really need to try to integrate all the examples sometime. Here&#x27;s a few, esp from past, that give you an idea.<p>Historical look at quite a few
<a href="http:&#x2F;&#x2F;brinch-hansen.net&#x2F;papers&#x2F;2001b.pdf" rel="nofollow">http:&#x2F;&#x2F;brinch-hansen.net&#x2F;papers&#x2F;2001b.pdf</a><p>Note: A number were concurrency safe, had a nucleus that preserved consistency, or were organized in layers that could be tested independently. UNIX&#x27;s was actually a watered down MULTIC&#x27;s &amp; he&#x27;s harsh on it there. I suggest you google it too.<p>Burrough&#x27;s B5000 Architecture (1961-)
<a href="http:&#x2F;&#x2F;www.smecc.org&#x2F;The%20Architecture%20%20of%20the%20Burroughs%20B-5000.htm" rel="nofollow">http:&#x2F;&#x2F;www.smecc.org&#x2F;The%20Architecture%20%20of%20the%20Burr...</a><p>Note: Written in ALGOL variant, protected stack, bounds checks, type-checked procedure calls dynamically, isolation of processes, froze rogue ones w&#x2F; restart allowed if feasible, and sharing components. Forward thinking.<p>IBM System&#x2F;38 (became AS&#x2F;400)
<a href="https:&#x2F;&#x2F;homes.cs.washington.edu&#x2F;~levy&#x2F;capabook&#x2F;Chapter8.pdf" rel="nofollow">https:&#x2F;&#x2F;homes.cs.washington.edu&#x2F;~levy&#x2F;capabook&#x2F;Chapter8.pdf</a><p>Note: Capability architecture at HW level. Used intermediate code for future-proofing. OS mostly in high-level language. Integrated database functionality for OS &amp; apps. Many companies I worked for had them and nobody can remember them getting repaired. :)<p>Oberon System
<a href="http:&#x2F;&#x2F;www.projectoberon.com&#x2F;" rel="nofollow">http:&#x2F;&#x2F;www.projectoberon.com&#x2F;</a>
<a href="http:&#x2F;&#x2F;www.cfbsoftware.com&#x2F;modula2&#x2F;Lilith.pdf" rel="nofollow">http:&#x2F;&#x2F;www.cfbsoftware.com&#x2F;modula2&#x2F;Lilith.pdf</a><p>Note: Brilliance started in Lilith where two people in two years built HW, OS, and tooling with performance, safety, and consistency. Designed ideal assembly, safe system language (Modula-2), compiler, OS, and tied it all together. Kept it up as it evolved into Oberon, Active Oberon, etc. Now have a RISC processor ideal for it. Hansen did similar on very PDP-11 UNIX was invented on with Edison system, which had safety &amp; Wirth-like simplicity.<p>OpenVMS
<a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;OpenVMS" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;OpenVMS</a><p>Note: Individual systems with good security architecture &amp; reliability. Clustering released in 80&#x27;s with up to 90 nodes at hundreds of miles w&#x2F; uptime up to 17 years. Rolling upgrades, fault-tolerance, versioned filesystem using &quot;records,&quot; integrated DB, clear commands, consistent design, and great cross-language support since all had to support calling convention and stuff. Used in mainframe-style apps, UNIX-style, real-time, and so on. Declined, pulled off market, and recently re-released.<p>Genera LISP environment
<a href="http:&#x2F;&#x2F;www.symbolics-dks.com&#x2F;Genera-why-1.htm" rel="nofollow">http:&#x2F;&#x2F;www.symbolics-dks.com&#x2F;Genera-why-1.htm</a><p>Note: LISP was easy to parse, had REPL, supported all paradigms, macro&#x27;s let you customize it, memory-safe, incremental compilation of functions, and even update apps while running. Genera was a machine&#x2F;OS written in LISP specifically for hackers with lots of advanced functionality. Today&#x27;s systems still can&#x27;t replicate the flow and holistic experience of that. Wish they could, with or without LISP itself.<p>BeOS Multimedia Desktop
<a href="http:&#x2F;&#x2F;birdhouse.org&#x2F;beos&#x2F;byte&#x2F;29-10000ft&#x2F;" rel="nofollow">http:&#x2F;&#x2F;birdhouse.org&#x2F;beos&#x2F;byte&#x2F;29-10000ft&#x2F;</a>
<a href="https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=BsVydyC8ZGQ" rel="nofollow">https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=BsVydyC8ZGQ</a><p>Note: Article lists plenty of benefits that I didn&#x27;t have with alternatives for long time and still barely do. Mainly due to great concurrency model and primitives (eg &quot;benaphors&quot;). Skip ahead to 16:10 to be amazed at what load it handled on older hardware. Haiku is an OSS project to try to re-create it.<p>EROS
<a href="http:&#x2F;&#x2F;www.eros-os.org&#x2F;papers&#x2F;IEEE-Software-Jan-2002.pdf" rel="nofollow">http:&#x2F;&#x2F;www.eros-os.org&#x2F;papers&#x2F;IEEE-Software-Jan-2002.pdf</a><p>Note: Capability-secure OS that redid things like networking stacks and GUI for more trustworthyness. It was fast. Also had persistence where a failure could only loose so much of your running state. MINIX 3 and Genode-OS continue the microkernel tradition in a state where you can actually use them today. MINIX 3 has self-healing capabilities. QNX was first to pull it off with POSIX&#x2F;UNIX compatibility, hard real-time, and great performance. INTEGRITY RTOS bulletproofs the architecture further with good design.<p>SPIN OS
<a href="http:&#x2F;&#x2F;www-spin.cs.washington.edu&#x2F;" rel="nofollow">http:&#x2F;&#x2F;www-spin.cs.washington.edu&#x2F;</a><p>Note: Coded OS in safe Modula-3 language with additions for better concurrency and type-safe linking. Could isolate apps in user-mode then link performance-critical stuff directly into the kernel with language &amp; type system adding safety. Like Wirth &amp; Hansen, eliminates all the abstraction gaps &amp; inconsistency in various layers on top of that.
JX OS
<a href="http:&#x2F;&#x2F;www4.cs.fau.de&#x2F;Projects&#x2F;JX&#x2F;publications&#x2F;jx-sec.pdf" rel="nofollow">http:&#x2F;&#x2F;www4.cs.fau.de&#x2F;Projects&#x2F;JX&#x2F;publications&#x2F;jx-sec.pdf</a><p>Note: Builds on language-oriented approach. Puts drivers and trusted components in Java VM for safety. Microkernel outside it. Internal architecture builds security kernel&#x2F;model on top of integrity model. Already doing well in tests. Open-source. High tech answer is probably Duffy&#x27;s articles on Microsoft Midori.<p>So, there&#x27;s a summary of OS architectures that did vastly better than UNIX in all kinds of ways. They range from 1961 mainframes to 1970-80&#x27;s minicomputers to 1990&#x27;s-2000&#x27;s desktops. In many cases, aspects of their design could&#x27;ve been ported with effort but just weren&#x27;t. UNIX retained unsafe language, root, setuid, discretionary controls, heavyweight components (apps + pipes), no robustness throughout, GUI issues and so on. Endless problems many others lacked by design.<p>Hope the list gives you stuff to think about or contribute to. :)