2.1 Language Declared in Source

The Use the language declared in the source mode in DrRacket is a kind of meta-language, where the program itself specifies its language, usually through a #lang line.

More generally, when using the declared-in-source mode, the definitions window must contain a module in some form. Besides #lang, a Racket module can be written as (module ...). In any case, aside from comments, the definitions window must contain exactly one module.

In the details pane of the module language, some of the configuration options correspond to using various libraries and thus can be used without DrRacket. Here’s how, for the ones that are straightforward (the ones not mentioned here require more sophisticated configuration of various libraries).