Software program created with Arduino, an open-source electronics prototyping platform; contains source code written in the Arduino programming language; used for controlling an Arduino circuit board.

Arduino programs can be used to perform basic commands, such as making an LED blink, or complex functions, such as transmitting data over the Internet. Different Arduino boards are available for specific applications. NOTE: Arduino 1.0 saves sketch files with the ".ino" extension (derived from the last three letters of "Arduino"). Previous versions of the software saved sketches with a .PDE extension.