Jojen 
Jojen is an updated take on Joi's API. Joi has a very pleasant and fluent API, however it suffers from relatively poor performance, lacks language support, doesn't allow user-defined validation functions, and doesn't work well in a Browserify/Webpack frontend.
Jojens goals are to:
- Mostly match the Joi API with very few inconsistencies (see compatibility)
- Fixes the inconsistent parts of Joi (again, see compatibility)
- Perform reasonably well (currently ~5.2x the speed of Joi) in a reasonably small package (currently 13.5 KB)
- Support browsers, user-defined validations, and internationalisation.
In its current state, Jojen is very much a work in progress. The foundation is there, and we'll be adding more features and validations in the coming weeks.