Download the latest version:
For older versions or other downloads that are available, proceed to Download Page.
My public key is available at http://www.noc.uoa.gr/~avel/gpgkey.asc and at various public key servers.
You can grab the latest sources via SVN, as follows:
svn co https://email.uoa.gr/repos/squirrelmail/plugins/useracl/trunk useracl
Web interface to Subversion Code Repository
Very easy. Just untar it under Squirrelmail's plugin directory, and use configure/conf.pl or ./configure or vi config/config.php to add the plugin as usual.
Afterwards, copy useracl/config_sample.php to useracl/config.php and change the default values in case they do not satisfy you. This file is self documented with comments.