I have used to manage over 74 projects at the same time http://www.activecollab.com/ for business processes, provide electronic document circulation and delegated projects (or individual tasks) control and much more
You install it on your server and everyone can access on the web or via iphone etc their is no monthly fee to pay when you buy it and can add unlimited projects and people.
Its very powerful but it depends on your individual requirements of course.
I use it but need another tool for project planning for gantt charts and budgets like projectmanager.com
Currently combining http://www.activecollab.com/ for team collaboration and projectmanager.com for project planning as the project manager