Forgotten Systems!
        
        UNIX being a good thing is commonly taken as axiomatic. I don't
        particularly think it is; if anything, Unix's extreme minimalism
        and inconsistent design was destructive to the work that was being
        done in the 1960s and 1970s on advanced, feature-rich hardware and
        operating systems oriented toward high-level languages and high
        reliability. I'll probably expand this page at some point, but
        this is a quick list of the ones that are important to me.
        
        -------------------------------
        --- Burroughs Large Systems --- 
        -------------------------------
        The Burroughs B5000 was a high-level mainframe with tagged memory
        and a pure HLL OS (there was literally no assembler on the
        platform) in 1961. Buffer overflows were architecturally
        impossible. Some design decisions have aged poorly - the decision
        to make floating-point values the fundamental data type on the
        system, for instance - but B5000 influenced all later descriptor
        and capability systems. Burroughs Large Systems was a successful
        family and is still in widespread use today, although Unisys moved
        the product line to emulation in the mid 2010s.
        
        --------------------------
        --- IBM S/38 and IBM i --- 
        --------------------------
        The S/38 and the (compatible) AS/400 that succeeded it have all
        the guts of a well-designed object-oriented descriptor
        architecture and are commercially successful, with over 100000
        customer sites. A flat 128-bit persistent address space hosts a
        sea of objects and a relational DB cleanly mapped on top of them.
        
        Unfortunately, it has the mouthfeel of an IBM midrange OS and
        largely exists to run RPG.
        
        --------------------
        --- 432 and BiiN --- 
        --------------------
        Intel's iAPX 432 was an attempt to build a clean platform for
        state-of-the-art object/capability software to run on.
        Unfortunately it was fundamentally misdesigned, physically large,
        lacked mature software, and was largely a flop out of the gate.
        Thankfully, in a rare inverse example of the second-system effect,
        it was followed up by the 960MX - a conservative cap extension on
        Intel's well-regarded i960 RISC.
        
        The system intended to run on the 960MX, BiiN and its OSIRIS OS, 
        was everything an advanced system should be - user-friendly,
        approachable, and with a rich set of elegant object-oriented APIs.
        It was also cancelled immediately before release, while largely
        complete, due to a desire by Intel to cut their losses and return
        to prioritizing their safely-profitable PC business.
        
        -----------
        --- VOS --- 
        -----------
        Stratus's Multics-like fault-tolerant OS isn't an advanced work of
        object-oriented art, but is something nice on its own: a better
        general-purpose, "normal", server OS than UNIX. Its standard
        library is an absolute pleasure to develop with, and the OS is
        friendly and well-thought-out from top to bottom. I miss working
        with it every time I have to write C on UNIX.
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