Potential was written as an exercise in passing the full Promises/A+ spec. Emphasis is on adhering to the spec language and commenting the source code accordingly, so as to serve as an educational example. Extended methods such as catch, all, map, and spread are also included. Potential is neither performance-optimized nor designed for maximum safety in production use (e.g. providing type checks, antipattern warnings and similar). Instead, it concentrates on relatively straightforward source code written using recent language features. For a highly performant, feature-rich, robust promise library, check out Bluebird.