Q2A and PHPBB are 2 branches of my main website.
In other words..
website.com/q2a
and
website.com/phpbb
...
When I use the login box on any of the 3 branches, I want the SSO to log me in to all 3 branches.
When I use the search box on any of the 3 branches, I want it to search content from all branches.
When I click on a user profile on any of the 3 branches, I want it to always go to the same user profile page.
Is this possible? How?
Will I need to make a custom CMS and a custom Q&A PHP Script and a Custom Forums?
You can integrate them all to use a single userbase (and/or search index) for sure. However, unless you find a ready bridge that accommodates them all, you will need to:
May not be a trivial task. Then again, creating matching applications from a scratch isn't a trivial task either. But of course we should all create our own CMS and app frameworks. What else is there to do.