Software Freedom Day (or simply SFD) is an annual celebration of free software. The main goal of SFD is to increase public awareness of various types of free software, as well as to encourage people to use free software as much as possible.
Close to 500 teams from 90 different countries celebrate SFD all around the world. SFD is held on the third Saturday in September (at least since 2006). The event is organized/overseen by Software Freedom International, which is a non-profit organization.
How does it work?
Every team has complete control over what events they want to organize to celebrate SFD. These events often vary from open source workshops and demonstrations, to speeches that explain the uses and advantages of Open Source Software. Each team gets a dedicated page on the SFD wiki where they can provide more details about their plans, events times and so on.
The event has attracted quite a few high caliber sponsors, including Linode, Joomla and Google. The primary sponsor is Canonical Ltd. SFD gets a lot of coverage in open source software magazines, such as the Linux Magazine and Ubuntu User.
People from all around the world can join their local SFD teams or even register one of their own. Every year, local SFD teams are looking for people who can help them take event photographs, spread the word about the event, create marketing material, and host workshops/presentations about the benefits/uses of Open Software. If helping out your local SFD team sounds like something that you might want to do, check out their website for more information.