For a commented initial example, see: e. Coli K-12 MG1655 gene thrA.
KEGG does the visual maps well.
But BioCyc is generally better otherwise.
TODO human presumably?
I don't think it has any advantage over KEGG however, besides historical interest? Maybe slightly more manual layout and so more beautiful?
James Somers (rightly) likes to point to it as a "biology is awesome" thing.
Design software for synthetic biological circuit.
The input is in Verilog! Overkill?
Then it essentially maps to a standard cell library of biological primitives!