The (Marginal) Silliness of ZZT is a one-off experimental fork of ZZT by Alex West, made in April 2020, shortly after the release of the Reconstruction of ZZT. It contains a handful of example implementations of some commonly added features, as well as a couple more experimental additions. No worlds have been created for this fork.
Most of these features have found their way into more mature forks, such as FirmWeave.
These are experimental one-off features that have known issues in their implementation: