Here's an example of a "hello world" app:
with ( require( "fab" ) ) ( fab ) ( listen, 0xFAB ) ( /^\/hello/ ) ( tmpl ) ( "Hello, <%= this %>!" ) ( /^\/(\w+)$/ ) ( capture.at, 0 ) ( "world" ) ( 404 );
Note that development on (fab) is evolving very fast, and upcoming changes will break the current API. Though with native templating and an an optional parentheses-light style, they'll be worth it. Read about what's going to change, if you'd like, or follow @fabjs for updates.