The Onux JS++ compiler unifies types into a single type known as the unified external type. By providing a sound type system, declared types (such as a string) will never be incorrect, enabling development of more-reliable applications, said Roger Poon, CEO at Onux and the creator of JS++.
The technology is not open source, and Poon says the company is seeking to patent it, primarily as a defensive mechanism because companies like Facebook (with Flow) and Google (with AtScript and SoundScript) are working on the same problem. Developers will not have to pay any royalties to use JS++, he said. Onux's business model, however, includes selling support services and add-on libraries for purposes like charting and graphing. The standard library will be available for free.