'''The Simple Library''' is a collection of commands and utilities aimed towards assisting software development in Tcl. It provides elements I consider essential for good software engineering and/or medium to big projects development, such as a framework for regression testing, documentation almost resembling literate programming, centralized error handling and improved package handling as well as debugging aids such as a mechanism to ensure type consistency for command arguments and non-local variables which provides some of the benefits of strong typing. The Simple Library is written in pure Tcl itself, so that no compilation is needed to run it on Unix, Windows or Mac environments. Just unpack into one of the directories that Tcl searches for packages and you are done; Tcl version 8.0 or later is required. In the future, some sections are likely to be rewritten in C for improved performance. For bug reports, comments, request for features or code contributions please contact the author at mailto:jgil@gmv.es. The Simple Library web home is at http://simplelib.homepage.com/ . The news:comp.lang.tcl is the Usenet group for Tcl and The Simple Library discussion. There is a page devoted to The Simple Library in the Tcl Wikit at http://purl.org/thecliff/tcl/wiki/TheSimpleLibrary