The officially supported and free Arduino software is certainly a moving target. The alpha versions, ranging from the very first 0001 through 0022, evolved as the needs of the Arduino Team and the growing user base changed and matured.
The goal of a 1.0 version (Arduino Uno Punto Zero in Italian) was first announced on the Arduino blog on January 1, 2010 (
http://arduino.cc/blog/2010/01/01/uno-punto-zero). It was intended to coincide with the continued growth and development of the Arduino hardware and become a reference version, ready to shed its preliminary status. The new generation of hardware, the Arduino Uno and Arduino Mega 2560, were announced at Maker Faire New York City in September 2010.
At the time ...