You can install wordpress once and run all of your blogs in a network using wordpress multisite.
Easily manage all of your blogs with one sign in and control center ... and best of all - the platform is 100% free! easily create a blog farm in just a few minutes!
This functionality is available for every Wordpress install. Simply turn it on and start using it. But the best part is that you can manage everything from a single control panel. No more signing in to individual blogs to maintain them.
Here are some benefits to using multisiteover several standard installs:
Manage all of your sites from a single control panel
Manage all of your themes (or users themes) from one spot
Manage and restrict users plugin capabilities
Shared user accounts.
Better site performance on each blog
A single upgrade point for all your blogs
Make money from other people's content
Install it once and use for all your blogs