GNU `m4' is an implementation of the traditional Unix macro processor. It is mostly SVR4 compatible, although it has some extensions (for example, handling more than 9 positional parameters to macros). `m4' also has built-in functions for including files, running shell commands, doing arithmetic, etc. Autoconf needs GNU `m4' for generating `configure' scripts, but not for running them. GNU `m4' has been originally written by Rene Seindal, from Denmark. This is release 1.3. It is now to be considered stable. In the subdirectory `examples' you will find various m4 files, ranging from trivial test files to rather advanced macros. If you intend to use m4 seriously, you might find useful material down there. See the file COPYING for copying conditions. See the file THANKS for a list of contributors. See the file NEWS for a list of major changes in the current release. See the file INSTALL for compilation and installation instructions. By using `./configure --enable-changeword', you get an experimental feature which allows for changing the syntax of what is a "word" in `m4'. This might go away, so don't count on it yet. Send bug reports to . A bug report is an adequate description of the problem: your input, what you expected, what you got, and why this is wrong. Diffs are welcome, but they only describe a solution, from which the problem might be uneasy to infer.