Here is a list of php scripts for creating forum portal. They are responsive design, easy to edit and setup.
phpForum is an innovative web platform built with the help of php and mysql.
Tractor is a simple PHP and MySQL based internet forum.
This plugin extends Tickets with an Articles (aka Knowledge Base) storage section.
Easy forum is a ready script for forums. It’s easy to integrate and install in any website.
Korum is a simple yet clean forum board built with Kohana 3 PHP framework.