While installing XOOPS, I noticed the following:

using a MySQL password that contains a $-sign

The installation script can not handle $-signs. It will not incert the password fully into the mainfile.php, but rather stops where the $-sign appears, and incerts the language constant for the rest of the password.

Just wanted to let others know about this issue!

PS: using HTML-tags works fine in this forum when previewing, but when posted they appear instead of transforming the text!
(for demonstration purposes, I will leave the HTML-tags in my posting)