TroubleShooter

Pligg comes with a troubleshooter, which can be accessed by visiting /install/troubleshooter.php on your web server after uploading the Pligg files. The troubleshooter will check your CHMOD settings as well as your MySQL and PHP versions and PHP functions used by Pligg. If your server is fully-compatible with Pligg it will output green text at the end of each row. Any features that are missing or not up to date will appear as red text, and a help icon will appear next to the red text that you can click on for a detailed explanation of the problem. Even if some of these fields output red text, that does not mean that Pligg will not work on your server. Some rows being red simply mean that one or more features may not work on your site.

PHP

Pligg is mostly tested on PHP version 5, but there are reports that Pligg will work on PHP 4 servers. Because of our development test setups we recommend that you use PHP 5 whenever possible.

MySQL

Pligg has been tested on MySQL versions 4 and 5. We highly recommend that you use version 5 to maintain long term compatibility with Pligg, but Pligg will "mostly" work with MySQL 4.
Pligg will not work on MySQL 3.x or lower.

That's it!
Some extra features and modules have additional requirements not listed on this page.