These are some Frequently Asked Questions about this service, with some answers.
What is http://status.fsf.org?
http://status.fsf.org is a stream oriented social network service.
You can use it to write short notices about yourself, where you are, and what you're doing, and those notices will be sent to all your friends and fans.
You can also post event invitations, bookmarks, polls, and questions or other kinds of social broadcasts.
How is http://status.fsf.org different from Twitter?
Like Twitter, http://status.fsf.org is a light service with a stream-oriented interface. It uses @-replies, hashtags, provides search, and has private messages. It provides an API, and can be integrated with SMS systems. You can create lists.
Unlike Twitter, http://status.fsf.org allows more data than just plain text and links to travel across the network. You can install the StatusNet software that runs http://status.fsf.org on your own servers, since it's Free and Open Source software. You can make groups, and share privately with those groups.
You can make your site available only to people you choose. You can customize it with your own themes and plugins, or download plugins from the StatusNet site.
How is http://status.fsf.org different from Yammer, SocialCast, or Salesforce Chatter?
Like some enterprise social software services, StatusNet lets you share privately with other people in your company. You can use microapps to post richer kinds of data, use public and private groups to share with team members, use extended profiles to show more about yourself and your company, and review groups and users in a directory.
Unlike those other services, StatusNet is free and open source software. You can install it on your own servers. You can customize the theme and add plugins.