Actually, the Arduino Team has put quite a lot of work into designing the Arduino IDE to allow multiple versions to be installed on the same computer and co-exist nicely.
I am somewhat nubee, i have arduino pro mini got a 3D printer with Mega 2560, then got a Due board, which has been a pita with libraries, had to install the latest Arduino BETA, and had problems trying to get it to generate i2s timings for external audio dacs, i then saw the Teensy 3.1 with your audio shield and also picked up the vs1063 audio shield to try and 'play' with to see which one i want to use in my project (want to be able to get live mic reverb and possibly shift effects while playing a other SPI streaming audio to the DAC). Anyway, since the TeensyDuino doesn't work with the Arduino Beta, - you have said that Arduino team worked hard on allowing multiple version to be installed at same time. So, I tried to run the install for 1.05 again and it sees the BETA installed and tells me I have to Unistall the BETA before it will let me install the 1.05. So, what am i missing here? I need to have both the BETA and 1.05 running so I can develop for Teensy and Due at the same time. What am i doing wrong if that's what you meant that i should be able to run both at same time. I know, this is more an Arduino forum question, but, your the one who said this is possible, so i'll ask you first, thanks (If i had seen the specs on Teensy 3.1 before i saw the Due, I probably wouldn't have bothered with the Due, and if the Teensy 3.1 works as i hipe it will, then bye bye Due...