How to build a web software for multiple instances?
<p>I'm looking into some good solutions for developing web software that can be sold as it's own "instance" to clients. Something akin to how wordpress,tumblr, and fogbugz have their services set up. I am trying to think about the best approach to this problem, and how to build a system that can support this.</p>

<p>It'll be in a LAMP stack. I'd like to be able to have separate directories for uploads and databases, though it isn't necessary. Also, the easier the new deployment of a new instance, the better. What would you suggest for a way to structure such a project?</p>
