NASA's InSight mission successfully landed on Mars, and the author hosted a liveblog watch party for school children aged 9-10.
The liveblog featured a central webcast, a right column for questions, and a left column for moderator answers, with no sign-on required.
Peak viewership was 70 simultaneous viewers; dozens of questions were asked and answered, and many kids became interested in science.
Key features included rapid deletion of clutter, emoji support, and separate input for questions and answers, but lacked image pasting and participant 'snoozing'.
The technology used open-source software (powerblog) built with libh2o, jquery, SQLite, and other tools, designed for easy deployment and live updates via long-polling.