Autoconf is written on top of two layers: M4sugar, which provides convenient macros for pure M4 programming, and M4sh, which provides macros dedicated to shell script generation.
As of this version of Autoconf, these two layers still contain experimental macros, whose interface might change in the future. As a matter of fact, anything that is not documented must not be used.
|• M4 Quotation||Protecting macros from unwanted expansion|
|• Using autom4te||The Autoconf executables backbone|
|• Debugging via autom4te||Figuring out what M4 was doing|