Here, we collect unanswered questions. Please sort them into the correct place in rest of the FAQ when you answer them.
How can I make a graphic interface with MIT Scheme?
Is there a way to directly manipulate environments?
Do you mean Scheme environments, or operating system environments?
What actively maintained wikis, IRC channels, supplemental tutorials, and/or mailing lists would most help an independent adult - or motivated teenager for that matter - learn PLT Scheme with How to Design Programs?
http://schemecookbook.org/ (The Scheme Cookbook) and #scheme-on-freenode is a start.
category-scheme-faq
Since the "environment" depends upon the host computer, it cannot be specified in the Scheme standard. However, system access can be provided through the FFI or an extension library. See Chicken manual page 5.7.8 for an example.