Dno, pronounced dee-no, is a command-line tool for building software for Arduino and related single board computers. It is intended as an alternative to the Arduino IDE for building, loading and testing Arduino software.

It does not provide an editing environment. Instead, by allowing builds to be executed as simple commands, developers are free to use the editor/programming environment of their choice.

It also goes beyond what the original Arduino IDE offers by supporting unit testing of libraries and the creation of Doxygen-based documentation of code. In short, it aims to support the creation of professional-quality software for Arduino platforms.

Finally, it aims to be as simple to use as possible - requiring minimal configuration while providing maximal flexibility.