MyBB Community Forums

I was directed to MyBB from someone who said it should be easy to integrate an existing user database into the myBB forum system. Is this true? How easy would it be for me to strip out myBB's user auth and sign up system and replace it with my own?

I am not interested in starting my site from scratch and building it around any forum software, please don't suggest it.

I am an accomplished PHP developer looking for forum software that will be the easiest and most effective when trying to integrate this existing user database into a forum package.

Any help is appreciated! Thanks!

Take a look at the hooks MyBB offers. You will need to create a plugin which registers functions for the hooks dealing with membership. Which hooks you register depends on how integrated you want it to be. There are even hooks for logging in and out.