If you select the "Media Queries" option under "Extra" in the build tool, your Modernizr build will include a matchmedia.js-like function called Modernizr.mq()
(see the documentation). The code's basically the same as matchmedia as both were written by Paul Irish.
Respond.js isn't included in Modernizr, but Initializr can create an HTML5 Boilerplate build which includes Modernizr and Respond.js.