What is an Arduino?
Glad you asked, we have a great introduction page on Arduino, click here to read it.
How can I get an Arduino board?
You can buy an Arduino board from one of the distributors listed on the buy page. If you'd prefer to build your own, see the Arduino Single-Sided Serial board, which can be easily etched and assembled.
Is Arduino open-source?
Yes. The source code for the Java environment is released under the GPL, the C/C++ microcontroller libraries under the LGPL, and the schematics and CAD files under Creative Commons Attribution Share-Alike licenses.
I want to design my own board; what should I do?
The reference designs for the Arduino boards are available from the hardware page. They're licensed under a Creative Commons Attribution Share-Alike license, so you are free to use and adapt them for your own needs without asking permission or paying a fee. If you're looking to make something of interest to the community, we'd encourage you to discuss your ideas on the hardware development forum so that potential users can offer suggestions.
What should I call my boards?
If you're making your own board, come up with your own name! This will allow people identify you with your products and help you to build a brand. Be creative: try to suggest what people might use the board for, or emphasize the form factor, or just pick a random word that sounds cool. "Arduino" is a trademark of Arduino team and should not be used for unofficial variants. If you're interested in having your design included in the official Arduino product line, please see the So you want to make an Arduino document and contact the Arduino team. Note that while we don't attempt to restrict uses of the "duino" suffix, its use causes the Italians on the team to cringe (apparently it sounds terrible); you might want to avoid it.
How can I run the Arduino IDE under Linux?
See instructions for Ubuntu Linux, for Debian Linux, for Gentoo Linux, for Linux, or for Linux on PPC. This this forum thread has more information. Or, you can use Arduino from the command line, and not have to install Java.
Can I program the Arduino board in C?
In fact, you already are; the Arduino language is merely a set of C/C++ functions that can be called from your code. Your sketch undergoes minor changes (e.g. automatic generation of function prototypes) and then is passed directly to a C/C++ compiler (avr-g++). All standard C and C++ constructs supported by avr-g++ should work in Arduino. For more details, see the page on the Arduino build process.
Can I use a different IDE to program the Arduino board?
It is possible to compile programs for the Arduino using a Makefile and the command line. If you can get your IDE to run make, you should be all set.
Can I use an Arduino board without the Arduino software?
Sure. It's just an AVR development board, you can use straight AVR C or C++ (with avr-gcc and avrdude or AVR Studio) to program it.
Can I use the Arduino software with other AVR boards?
Yes, although it may require some modifications to the Arduino core libraries. See the other hardware page for details.
These questions have moved to the troubleshooting section of the Arduino guide.