@@ -13,4 +13,26 @@ Keep reading if you're planning to work on the Urbit interpreter, you're a
13language implementation geek, or you don't really understand anything until
13language implementation geek, or you don't really understand anything until
14you've seen the actual structs.
14you've seen the actual structs.
16−;list;
16+### [C runtime system](runtime)
18+The Urbit interpreter is built on a Nock runtime system written
19+in C, `u3`. This section is a relatively complete description.
21+### [c3: C in Urbit](c)
23+Under `u3` is the simple `c3` layer, which is just how we write C
26+### [u3: Land of nouns](nouns)
28+The division between `c3` and `u3` is that you could theoretically
29+imagine using `c3` as just a generic C environment. Anything to do
30+with nouns is in `u3`.
32+### [u3: API overview by prefix](api)
34+A walkthrough of each of the `u3` modules.
36+### [How to write a jet](jetting)
38+A jetting guide by for new Urbit developers.