Singling out Linux as the most successful open source project is not literally true in my opinion. It is successful, other projects are successful too - how do you want to determine "most successful"?
for the sake of just finding a counterproof to something I agree with: maybe perl for the second?
There is basically no *nix without perl (I recall it was also part of the MS build system for rotor), it has influenced basically every programming language in the last decade and it's been a dependency of the linux kernel build for a long time, though I seem to recall it's now removed :)
