Also, this project is designed for operating systems other than Plan 9.

IBM systems have the famous Red Books, but ok it isn't included.

Windows before the Internet days, when the SDK came in CD, having a MSDN subscription meant receiving a box with all documentation from Microsoft.

Inferno as Plan 9's successor also included all documentation.

Niklaus Wirth OSes for Modula-2 and Oberon, had the OS documentation as hypertext.

All Xerox PARC OSes, across Smalltalk, Interlisp-D and Mesa/Cedar had online help with the system documentation.

echo kill > /proc/123/ctl

Sure, that works if you know kill, but you cannot inspect ctl and understand the interface, its a write interface. so you can certainly RTFM, read the dev proc list, etc. it's not discoverable

so like /proc/net/stat or whatever, it means nothing to me... its gonna just be a TSV of bytes that mean something, unless you know it.

so for all the simplicity, it's what i would call, not very usable.

I've spent a lot of time with these 'kludges' as well as all of the alternatives available and I far prefer the kludges. They make working with resources remote or local a breeze, they allow the same software to work with a COM port or a SCSI channel, they allow for all kinds of abstractions and get rid of an enormous amount of cruft in code to special case each and every device under the sun.

The 'Unix' version of that statement is the one that is kludgy, I'll give you that. But I was looking well beyond Unix, see TFA.

The C compiler is there, the same way as in Plan 9, Inferno is the evolution of Plan 9, in one way it was Bell Labs response to Java, in other way it was another take to what went wrong in Plan 9 like the failure to design Alef to be usable.

Naturally Limbo was prefered as the main userspace language, from safety and usability point of view.