Indeed, a strange one to pick. I&#x27;d even say that if portability isn&#x27;t a concern, working with x86_64 assembly is quite pleasant. If you avoid the lure of premature optimization, and stick with either function oriented, or at least procedure oriented programming, without too many long jumps -- I think you could get on quite fine in assembly.<p>The biggest issue, might be one that (sadly too) many low-level languages share: with the move to UTF-8 as the only sane choice for text, there are no string&#x2F;char datatypes any more. No reason one can&#x27;t use procedures&#x2F;functions to deal with strings in assembly, but it would require a bit more planning than in a language that have &quot;native&quot; UTF-8 support.<p>[ed: I think Kollibri OS proves both points: it&#x27;s a working OS, but they&#x27;ve yet to port from 32bit to 64bit even though they upstream they forked from (Menuet OS) has a 64 bit version (that&#x27;s not Free software&#x2F;open source).<p><a href="http:&#x2F;&#x2F;kolibrios.org&#x2F;en&#x2F;" rel="nofollow">http:&#x2F;&#x2F;kolibrios.org&#x2F;en&#x2F;</a><p>Another &quot;big&quot; asm OS project is: <a href="https:&#x2F;&#x2F;github.com&#x2F;ReturnInfinity&#x2F;Pure64" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;ReturnInfinity&#x2F;Pure64</a> ]