When comparing Babel (6to5) vs PharoJS, the Slant community recommends Babel (6to5) for most people. In the question“What are the best languages that compile to JavaScript? ” Babel (6to5) is ranked 8th while PharoJS is ranked 13th. The most important reason people chose Babel (6to5) is:
Babel will turn your ES6+ code into ES5 friendly code, so you can start using it right now without waiting for browser support.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Support ES6(Harmony)
Babel will turn your ES6+ code into ES5 friendly code, so you can start using it right now without waiting for browser support.
Pro Plugins for custom features
Pro Future forward thinking
Pro Program the web in Smalltalk
For people who enjoy programming in Smalltalk, Pharo allows developers to use Smalltalk for web development as well, since it transpiles Smalltalk code to JavaScript.
Pro Support for Phonegap to go directly to iOS/Android mobile App
Pro Compiles to very efficient Javascript, with almost perfect Smalltalk semantics
Pro Great IDE support
Pro Seamless integration with JavaScript libraries
Can directly call to / be called from JavaScript and can use foreign JavaScript objects.
Will soon have ability to generate and use AMD modules.
Cons
Con Generated ES5 is ugly and performs badly
Output looks far from handwritten ES5, is quite large with a lot of extra statements to execute.