I've seen pictures that were done by multiple people on a single canvas and apparently they all/both worked on it at the same time. but for the life of me i can't remember what they said they were using.. I THINK it was something like OpenCanvas.. I have some friends i would like to doodle with but need a program to use since none of us live anywhere near each other..

Any idea something we could use? preferably something free but so long as its not super expensive i'll look into it.