At the very beginning (back in 2005) it was mostly a distribution, but during the last 12 years an enormous amount of new code (over 500K SLOC) has been written

At the very beginning (back in 2005) it was mostly a distribution, but during the last 12 years an enormous amount of new code (over 500K SLOC) has been written, building on top of that distribution. You can get a sense of the scale and velocity of development here: https://github.com/sagemath/sage/graphs/contributors https://github.com/sagemath/sage/graphs/contributors