User restrictions
This module is a replacement for the 'access rules' functionality which was removed from Drupal 7 [1].
There will be no releases for Drupal 5 or Drupal 6, if you're looking for this functionality in either of those versions, try admin/user/rules. You are most likely to need this module if upgrading from Drupal 6.x or earlier with existing access rules in place. A stripped down version of IP address blocking was left in core [2], so this module will focus on usernames and e-mail addresses, at least for the time being.
The current code is essentially a find and replace of functions that were removed in #228594, it's completely untested and non-functional. Initial plan is to fix the bugs and omissions introduced from moving the code into a separate module and get the tests working. Once it's functional again, I'll be revisiting much of the old code and UI and keeping up with HEAD before adding any new features.
[1] Issue: http://drupal.org/node/228594 Commit: http://drupal.org/cvs?commit=109678
[2] http://api.drupal.org/api/function/drupal_is_denied/7