Macsyma had a notebook long ago, which probably inspired Mathematica notebooks. Those inspired an early IPython non-web notebook, developed by some UCSD studen

Macsyma had a notebook long ago, which probably inspired Mathematica notebooks. Those inspired an early IPython non-web notebook, developed by some UCSD students in 2006. They demoed it at Sage Days 1 then, and me, Alex Clemesha, and Tom Boothby spent 2006-2007 that building the first version of the Sage notebook. Then a 16 year old kid in the Philippines (Tim Dummol) did a truly massive amount of development on the Sage notebook. Mike Hansen and Robert Bradshaw (lead dev of Cython) also did a lot around then. Then we all kind of got tired of working on the Sage notebook, and I think Tim went off to college, and it started to linger. IPython (now Jupyter) then got going in around 2011, with very strong grant support from the Moore and Sloane foundations, which Fernando Perez (and others) put a huge amount of work into getting. In 2013, I bit the bullet and got back to web development (SaaS is really important to bring open source to the masses), and have been working fulltime (now with a team!) on SageMathCloud since then.