Here is a list of all documented files with brief descriptions:

[detail level 123]

include
metalang99
assert.h	Static assertions
bool.h	Boolean algebra
choice.h	Choice types: (tag, ...)
control.h	This module is deprecated and exists only for backwards compatibility
either.h	A choice type with two cases
gen.h	Support for C language constructions
ident.h	Identifiers: [a-zA-Z0-9_]+
lang.h	The core metalanguage
list.h	Cons-lists
logical.h	This module is deprecated and exists only for backwards compatibility
maybe.h	An optional value
nat.h	Natural numbers: [0; 255]
seq.h	Sequences: (x)(y)(z)
stmt.h	Statement chaining
tuple.h	Tuples: (x, y, z)
util.h	Utilitary stuff
variadics.h	Variadic arguments: x, y, z
metalang99.h