Arduino is a hardware and software eco-system for education and quick prototyping of electronics. The hardware is mainly around micro-controller family that now is expanding with more powerful ARM MCUs. The software is Integrated Development Environment (IDE) supporting complete family of 50+ official boards + 1000s of third party variant boards.
The Arduino project was started in 2003 at the Interaction Design Institute Ivrea (IDII) by a team consisting of Massimo Banzi, David Cuartielles, Tom Igoe, David Mellis and Gianluca Martino. The project goal was to create simple, low cost tools for creating digital projects by non-engineers.