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title: Developer doc
sort: 2
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# Developer documentation

Urbit has three programming layers: Nock (combinator nano-VM),
Hoon (strict functional language), and Arvo (functional OS).

To code in Urbit, the least you need to learn is Hoon, plus a
little bit of Arvo.  Nock is a sort of functional assembly
language -- you don't need to know it, but it's useful to.
Nock is also the easiest thing in the world to learn.

You can program for Arvo without knowing much about Arvo
internals, but again it helps.  But you need to know Hoon.
Don't worry, 

Alas, the developer doc is still under construction.  We'll have
more soon, starting with Nock.

<list></list>

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