+.SH WINDOWS
+On Windows systems, it it necessary to have Unix-like toolchain to be
+installed for mkbundle to work. You can use cygwin's and install gcc,
+gcc-mingw and as packages.
+.SH ENVIRONMENT VARIABLES
+.TP
+.I "AS"
+Assembler command. The default is "as".
+.TP
+.I "CC"
+C compiler command. The default is "cc" under Linux and "gcc -mno-cygwin"
+under Windows.