NEXTSTEP, OSF 3.2, IRIX, and Rhapsody once upon a time.
The current maintainer does not have access to these systems, and assumes that
-the system is at least Single-Unix-Specification V2 compatible, yet fetchmail
-should be compilable by a C89 compiler. It currently ships with a copy of the
-trio library for systems that lack snprintf(). A further requirement is that
+the system is at least Single-Unix-Specification V3 compatible, and that
+will also require a C99 compiler. A further requirement is that
either realpath() permits its 2nd argument to be NULL for auto-allocation,
or that otherwise PATH_MAX be defined.
-Fetchmail should be able to be compiled with C89, C99, C11, C++98, C++03,
+Fetchmail should be able to be compiled with C99, C11, C++98, C++03,
C++11, C++14 compilers, but not C++17 because the "register" keyword is
used in some parts of the code.