Richard P Gabriel: "Engineering often precedes science. Incommensurability is real."
Extensive list of free programming books, maintained on github.
Ruby is a powerful language, but how much power does it have if you remove all of its datatypes except for Proc and all of its features except for Proc.new and Proc#call? I’ll investigate by building proc-only representations of numbers, booleans, lists and strings, and using them to write an executable program.