This is a micro framework which can be used in conjunction with the DOME engine to make simulation-based games in Wren.
Warning: This framework is an undocumented work in progress, but iterations of it have already been used in different jam projects.
It provides core classes for a World, made of up Zones (with an associated map), which contains a collection of entities.
Entities declare their actions, represented by discrete Action classes, which the engine then executes to modify the world state.
Parcel also keeps a strict seperation between the UI and the world "model", which allows for greater flexibility.
Various components of Parcel are hot-swappable: For example, Parcel allows for both real-time and turn-based games using the scheme above.
The core architecture was proposed in this article by Bob Nystrom before it was adapted for DOME by Aviv Beeri.