For anyone interested: http://community.invisionpower.com/ What do you think? I see some interesting things like: When viewing a thread you can see how many "followers" that thread have. @Chris D coded something similar: https://xenforo.com/community/resources/thread-watchers.1205/ When viewing a thread you can navigate from page A to page B without reloading the page, just AJAX (might hurt those selling ads based on pageviews). Their stock theme looks more mature than the default XF theme which looks like a child's site (mainly due to the color combination). However the responsive version of XF looks way better than the responsive version of IPS4. What do you think about IPS4?