one-file (1f) project is a collection of utilities and tools primarily written for console use, with text output, or using SDL 1.2 for "gui stuff.
When individually compiled, the source is appended, either as TEXT, or ZIP, to the resulting binary. That source contains command line options to extract that source, as well as the command line used to compile said source.
There are no hard and fast rules, except "name-1f", must append source, and source must contain compile time command, and any "depends" info.
one-file (1f) is based on an original idea implemented in the 1990's Windows app Spasm.
Either download all sources in the zip, or get the individual source files from the project homepage.
SDL coding is not bound to any windowing system.