(CircuitLab developer here.) Thank you for the kind words! :) Clickable link: https://www.circuitlab.com/ if anyone wants to give it a try.
As far as the linked article "Fifty Nifty Variations of Two-Transistor Circuits: A tribute to the versatility of MOSFETs", I will mention that CircuitLab does NOT currently provide a MOSFET model that includes a separate body terminal.
Instead, the body (also sometimes called the "back gate") and source terminals are assumed to always be internally connected in the CircuitLab MOSFET models, resulting in a three-terminal device.
As far as the linked article "Fifty Nifty Variations of Two-Transistor Circuits: A tribute to the versatility of MOSFETs", I will mention that CircuitLab does NOT currently provide a MOSFET model that includes a separate body terminal.
Instead, the body (also sometimes called the "back gate") and source terminals are assumed to always be internally connected in the CircuitLab MOSFET models, resulting in a three-terminal device.
Almost all real-world discrete MOSFETs you can buy are also three-terminal (gate/drain/source), not four (gate/drain/source/body). Some discussion here https://electronics.stackexchange.com/questions/137161/why-a... and here https://electronics.stackexchange.com/questions/185109/mosfe... but not especially satisfying in my opinion.
As a result, Figures 2, 16, 27, 29, 46, 49, and 50 can NOT currently be realized within CircuitLab.