This is a guest blog post written by Andrea, you can catch her work at, WPMUTutorials.com. You can also follow her on Twitter

With the recent news coming out of WordCamp San Fransisco, and even the buzz from WordCamp RDU, interest is high in WordPressMU, the multi-blog version of single WordPress. We don’t know when, exactly, the merge of the two will be rolled into one package and released, but more code is being blended almost every day.

In case you haven’t checked out WordPressMU, not only is it the software that powers wordpress.com, and has a much talked about plugin suite called BuddyPress, it is flexible enough to power multiple blogs on separate domains.

So what can you do with WordPressMU, that you will soon be able to do with WordPress itself?

Power your own blog network with sub-blogs in the form of blogname.yourdomain.com or yourdomain.com/blogname. The can lead to extensive navigational possibilities that were previously only accomplished by multiple installs or tricky uses of categories.

Power multiple blogs, each off their own domain, on one codebase with one database. No hacks, no tricky configs, no extra files laying around.

Set up a great development site for clients. Instead of a separate install, or working on one at a time, give each client their own working blogs. You can restrict access to certain users who are only logged in and assigned to that particular blog via privacy plugins.

Have super powers. In MU, there’s a default admin user created on installation. This admin is known as the Site Admin and can get in the backend of any blog and edit any information at any time, regardless of blog assignment. You can even add users as co-site admins.

Have multiple Sites in one install. More so than just a separate domain, each Site within a MU install is able to have their own blogs. So you can have MU within MU.

Adding another blog is as simple as revisiting the signup page, or filling out three fields in the backend and clicking a button. Presto! Another blog is created with all the themes you allow access to, and all the plugins already installed.

One thing to remember is that since you are working with one codebase and multiple blogs, they are all stored virtually in the database. The files on the server will be pretty familiar – there’s one theme folder, one plugins folder and a mu-plugins folder for auto-executed plugins. These are plugins that are always on and don’t show in the Plugins menu in the backend. Not all plugins will run from this folder. Since there’s one folder for each, all blogs will share everything in them. Each blog does have their own folders for blog-specific uploads, however.

What does this mean for the general WordPress community? I think it’s huge and exciting news that really pulls WordPress to the forefront of a great website – not “just” a blog, we can all have easy access to truly push-button publishing. Or more blogs, as it will be all rolled in.