CALISTO is a series of regular-difficulty high school question sets head-edited by Justine French. In the first edition of the set, the name stood for CALIfornia Spring TOurnament, reflecting the fact that its primary contributors were Californian; however, the second edition was specified not to be an acronym.
The first iteration of CALISTO was first mirrored in January 2020. It was edited by Justine French, Shahar Schwartz, Avinash Iyer, Jeffrey Ma, Anishka Bandara, and Alistair Gray and written by a team of exclusively Californians. Unlike most high school sets, which have 4 science tossups and 4 science bonuses per packet, CALISTO 1 used an experimental distribution of 4.5 science tossups and 4.5 science bonuses to make more room for "Other Science."
The second iteration of CALISTO was first mirrored in fall 2021, two seasons after the previous iteration. Unlike the first CALISTO, this iteration had an open application for writers and editors, though its writing team still possessed a plurality of Californians. CALISTO 2 was edited by Justine French, William Orr, Govind Prabhakar, Arthur Delot-Vilain, Dylan Bowman, Shahar Schwartz, Eric Yin, Alistair Gray, Rohan Venkateswaran, Jeffrey Ma, Nick Dai, and Tasis Gemmill-Nexon.