Blender is what I point to when people tell me open source is doomed for failure. There isn't anything that comes remotely close in terms of features and ubiquitous support, and its free. Honestly the best example of open source done right.
And on the brink of not existing at a couple of times in its history, reinforcing how tenacious you have to be :) Huge Kudos to Ton who've been through hell and back for Blender to end up what it is today.
