This package requires PHP 5.x and the following PHP Pear libraries:

- DB_DataObject http://pear.php.net/package/DB_DataObject
- Validate http://pear.php.net/package/Validate
- XMLWriter (built-in)
- Auth_Yadis from OpenIDEnabled (not the PEAR version!). I decided
  to use the openidenabled.com version since it's more widely
  implemented, seems to be better supported, and it may make sense to
  use the openidenabled.com libraries for OpenID auth sometime in the
  future. Note that this is no longer distributed separately; it's only
  in the openidenabled.com OpenID PHP tarball.
  http://openidenabled.com/php-openid/
- OAuth.php from http://oauth.googlecode.com/svn/code/php/
- markdown.php from http://michelf.com/projects/php-markdown/ 
- PEAR Mail, for sending out mail notifications
- PEAR Net_SMTP, if you use the SMTP factory for notifications