MPICH comes with both an installation guide [25] and a user's guide [27]. Although there is some overlap, and therefore some duplication, we consider separating them to be a better approach than combining them. Although many users obtain and use MPICH just for their own use, an increasing number of them are linking their own programs to a system-wide copy of the libraries that have been installed in a publicly accessible place. For such users the information in the installation guide is a distraction. Conversely, the user's guide contains a collection of helpful hints for users who may be experiencing difficulties getting applications to run. These difficulties might well never be encountered by systems administrators who merely install MPICH.
An important but frequently overlooked part of a software project (particular for research software) is the generation of documentation, particularly Unix-style man pages.This is not to say that the format of man pages cannot be improved; rather, every Unix user knows how to get information this way and rightly expects man pages to be provided. We use a tool called doctext [22] that generates man pages (as well as WWW and LaTeX documentation) directly from simple, structured comments in the source code. Using this tool allowed us to deliver MPICH with complete documentation from the beginning. Examples of the documentation can be accessed on the WWW at http://www.mcs.anl.gov/mpi/www/index.html.