Custom JsModelMapper
All you need to do is creating a new class, which derives from IJsModelMapper.
The only method which you have to write is GetJs.
It takes the IJsModel as parameter, which exposes the name, jsNamespace, properties, validation-properties and more.
JsMapper.Mappers
Take a look at the JsMapper.Mappers-Namespace.
You'll find the JsModelMapper for Backbone and KnockoutJS.