Motives Engine

The Motives Engine is a Sims-inspired simulation engine developed by Tony Bark. Although it borrows elements from all four games, the engine itself wholly unique in its implementation. The virtual machine, the part that makes modding and expansions possible, shares more in common with BarkVM and Second Life's LSL than The Sims.

Basil VM

Basil (BASIC Application Scripting for Item Logic) is the scripting language and virtual machine. It optionally allows developers to extend an object's functionality beyond fixed motives.

The VM uses JSON as an intermediate representation (IR) with a schema inspired by WebAssembly. Bark argued that he is just one person and that an intermediate language (IL) are technically two different concepts. Because JSON is provided for free with popular programming languages, he wasn't going to write another language if he didn't have to.