Arduino is an open-source project and we’re happy that so many people have created variations on our hardware and software. We realize, however, that it’s sometimes hard to tell which products are part of the Arduino platform itself. The official boards are listed on the hardware page (and pictured above, with the exception of the official shields and Mini-USB adaptor). These are the products that we feel provide the best overall experience and utility to the Arduino community. They include boards from three manufacturers: SmartProjects (in Italy), SparkFun, and Gravitech (both in the US). These companies pay a licensing fee in exchange for support for these products in the Arduino software and documentation.
The official Arduino products are the only ones licensed to use the word “Arduino” in their name. Other products may be labelled as “Arduino-compatible” or “for Arduino”, but these are not a part of the platform itself and don’t fund continuing work on the project. If you’re making a product and wondering what to call it, we’ve added some guidelines to the FAQ. We think that these conventions make it easier for everyone to understand what products they’re buying and who supports them.
Finally, we’d like to thank a few companies that have been particularly good about working with us on these issues: Adafruit Industries, Oomlout, and SparkFun Electronics. Thanks for your cooperation and all the great products!