(fab) is a lightweight toolkit that makes it easy to build asynchronous web apps. It takes advantage of the flexibility and functional nature of javascript to create a concise "DSL", without pre-compilation or magic scope hackery.
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 );
See more examples, learn how to make your own apps, or see the apps that (fab) provides for you.
Note that subsequent development on (fab) breaks the current API, and is happening over at the v0.5 branch, so check there to see where things are heading.