DrScheme is a Scheme development environment for building applications that run on MzScheme or MrEd. It features intuitive syntax checking, an REPL for testing modules and much more. It is a complete environment for teaching programming and comes with a set of graded "languages" that a tutor can expose students to.
Programming tutorials such as HtDP (How to Develop Programs) and "Teach yourself Scheme in fixnum days" come bundled with this IDE.