Let's say I have a server and a bunch of developers working on different sites(php and django) and I don't want the different developers to access each other's sites.
How should I go about implementing such a solution? (some pointers will do)
i think, under apache suEXEC will do the job.
Antoine is right. You can check this link for setting up a apache-suphp webserver.
suPHP is a tool for executing PHP scripts with the permissions of their owners. It consists of an Apache module (mod_suphp) and a setuid root binary (suphp) that is called by the Apache module to change the uid of the process executing the PHP interpreter.
In suphp configuration the files must be in the ownership of the user, other wise php file requests will end up in Internal Server error.