WordPress Multi User is a powerful personal publishing platform, and it comes with a great set of features designed to make your experience as a publisher on the Internet as easy, pleasant and appealing as possible.
Who else is using WordPress MU?
Newspapers and magazines, like Le Monde.
Universities, like Harvard.
Niche-specific blog hosts, like Edublogs
How much code does it share with regular WordPress?
Basically WordPress MU is a wrapper around the core WP code that virtualizes multiple blogs. The code that differs is in some bootstrap files, and administration for multiple blogs and users. It's tough to say exactly what percentage of the total code this comprises, but it'd be safe to say that 95-99% of MU is core WP.
Can blogs have multiple authors?
We offer unlimited blogs, with unlimited authors on them, and even users who don't have any blogs at all. Users can have different roles (editor, admin, author) on different blogs. The possibilities are only limited by your imagination.
Do plugins work?
Plugins work just like in regular WordPress, they can be activated and deactivated on a per-blog level. We have something extra called "mu-plugins" which auto-executes any PHP file in that directory, like plugins that are enabled by default. Most plugins work, but some that modify core tables or create tables of their own in the DB might have difficulties, depending on how they're coded. Best way to find out is to test!
Do themes work?
In theory a theme could work with WP but not MU, but we've never run into one. So yes, all themes work. In fact, we have provided you with 100 themes and there are more on the way. Incidently you can modify a theme or you can even create your own.
Does it support regular domains in addition to sub-domains?
Sure, to MU a domain is just a domain. You can configure it to respond to any top-level domains or subdomains.
In order to be able to offer you free-of-charge subdomains the arrangement is http://engineer.net.au/your-blog however in time if your will to pay a small fee the alternative arrangement is