But when Arduino LLC tried to register the Arduino trademark, it turned out Gianluca Martino had registered the trademark for his own company two years prior, and not told the others. (Arduino LLC got the trademark in the USA, but were not able to register it anywhere else) This happened in 2008. At the time, they just agreed to stay friends and not make a big deal of it.
Then, last year, Smart Projects SRL made a big deal of it. They renamed their company Arduino SRL, registered arduino.org and cut their ties to Arduino LLC. This was reportedly because LLC wanted to start licensing the name to other manufacturers, but SRL wanted to keep official Arduino manufacturing to themselves. This led to the arduino.cc/arduino.org split.
That's pretty sleazy and anti-open source of them if you ask me.
https://arduinohistory.github.io
I think it's really appaling how the original inventor is (not) credited.
http://hackaday.com/2015/03/12/arduino-v-arduino-part-ii/
For a long while, most people didn't understand the turmoil in the arduino market. The competing arduino.srl tried to fork the ide and even the history of the project.
Here's a direct statement from Banzi Massimo: http://makezine.com/2015/03/19/massimo-banzi-fighting-for-ar...