I wonder if they looked at:

http://mcavage.github.io/node-restify/

Both self describe as frameworks.

in a quick blurb on express v restify: "I get asked this more than anything else, so I'll just get it out of the way up front.

Express' use case is targeted at browser applications and contains a lot of functionality, such as templating and rendering, to support that. Restify does not."

FWIW I am a backend guy and have enjoyed prototyping and working with restify a great deal ( dtrace ftw :) ), just a user and YMMV of course.