Yes. CPU Land is free and does not ask you to register or hand over an email address before you can use it.

How long does CPU Land take?

Clear your evening. We warned you. We file it under "Rabbit hole" — what happens between typing a command and seeing output.

Does CPU Land work on a phone?

Yes. CPU Land works on a phone as well as it does on a laptop.

Explain Everything

CPU Land

What happens between typing a command and seeing output

Visit cpu.land More Explain Everything

cpu.land

Rabbit hole · Works anywhere

Free, no sign-up · online since 2023

What CPU Land actually is

A single long article tracing how a program actually runs, from the shell's fork and exec through system calls, kernel mode, interrupts, virtual memory and the scheduler. Diagrams and short asides break it up, and it assumes only that you have used a terminal before.

Why it is worth your time

It answers the question most programmers quietly avoid, which is what the operating system is doing while your code waits, and does it in one sitting.

Common questions

Is CPU Land free?: Yes. CPU Land is free and does not ask you to register or hand over an email address before you can use it.
How long does CPU Land take?: Clear your evening. We warned you. We file it under "Rabbit hole" — what happens between typing a command and seeing output.
Does CPU Land work on a phone?: Yes. CPU Land works on a phone as well as it does on a laptop.
What kind of site is CPU Land?: We list it under Explain Everything — hard things, made suddenly obvious. It answers the question most programmers quietly avoid, which is what the operating system is doing while your code waits, and does it in one sitting.

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Explain Everything

CPU Land

What happens between typing a command and seeing output

Visit cpu.land More Explain Everything

cpu.land

Rabbit hole · Works anywhere

Free, no sign-up · online since 2023

What CPU Land actually is

Why it is worth your time

It answers the question most programmers quietly avoid, which is what the operating system is doing while your code waits, and does it in one sitting.

Common questions

Is CPU Land free?: Yes. CPU Land is free and does not ask you to register or hand over an email address before you can use it.
How long does CPU Land take?: Clear your evening. We warned you. We file it under "Rabbit hole" — what happens between typing a command and seeing output.
Does CPU Land work on a phone?: Yes. CPU Land works on a phone as well as it does on a laptop.
What kind of site is CPU Land?: We list it under Explain Everything — hard things, made suddenly obvious. It answers the question most programmers quietly avoid, which is what the operating system is doing while your code waits, and does it in one sitting.