Hello !
I have just started reading about XOOPS for two days.
I would like to ask how can I run existing XOOPS project in Ubuntu.

I copied the old contents in Apache's (var/www/) folder and pasted them in mine , but the XOOPS could not run properly , without any errors message.

I was about to install XOOPS in my Ubuntu , then I saw that XOOPS must be copied onto /var/www/ too , but I do not see that folder in the old Ubuntu.

Does Xoops add lib into Ubuntu machine or inside Apache server ?

Help me please !

BTW , I thank you for your time.

This will depend on the version of PHP, MySQL and XOOPS you are trying to use. You can find the version of XOOPS you are using in ./include/version.php file. If you will post the PHP, MySQL and XOOPS versions back here we can help you get your existing project to run.