People who are really serious about software should make their own hardware.

Alan Kay made this remark in the milieu of 1970s–1980s personal computing research, when he and colleagues at Xerox PARC were exploring radically new software ideas (object-oriented programming, graphical user interfaces, dynamic media) alongside novel machine designs. Kay often argued that the capabilities and constraints of hardware shape what kinds of software are feasible and what kinds of ideas programmers even imagine. The quote reflects a research culture in which building complete systems—hardware, operating system, languages, and applications—was a practical route to innovation (as with the Alto and later Smalltalk systems), rather than treating hardware as a fixed, external platform.

The line is a provocation: if you care deeply about software, you should not accept the underlying machine as given. Kay’s point is that software abstractions ultimately rest on hardware realities—memory models, I/O, display, latency, and instruction sets—and that transformative software often requires rethinking those foundations. “Make their own hardware” can be read literally (designing new machines) and metaphorically (taking responsibility for the whole stack). The quote also critiques a tendency to optimize within existing constraints rather than changing the constraints themselves, suggesting that real breakthroughs come from co-designing tools, languages, and the machines they run on.

1) “People who are really serious about software should build their own hardware.”
2) “If you’re really serious about software, you should make your own hardware.”