That doesn't really change what MatthewPhillips said. "Framework" can mean everything from Rails to startup.sh that boots up your node process. Express really doesn't do much, and is closer to middleware than a full framework.
Not to stop there, it's in the page title too, so anyone coming in from Google (for example) is basically required to click on the phrase "web application framework" and acknowledge that the creators, at least, think that it's a framework.
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.
