JUniversal vs Onsen UI: What are the differences?

What is JUniversal? A new, Java-based approach to cross-platform mobile apps (used by Google Inbox and Google Spreadsheets). The vision of JUniversal came from some guys at Nokia who possess considerable expertise both in Java and in building cross-platform apps. They built this tool to provide an elegant way to translate source code and make it useful across multiple platforms. JUniversal offers you the freedom to write your shared code in Java and then translate it to C# (available now) or to C++/Objective C++ (coming soon). You can also combine JUniversal with Google’s j2objc translator to translate Java to Objective-C for iOS.

What is Onsen UI? HTML5 Hybrid Mobile App UI Framework - work with Angular, React, Vue, Meteor & pure JavaScript. Material & Flat design. Onsen UI helps you develop both hybrid and web apps. If developing hybrid apps, you can use it with the Cordova / PhoneGap command line, or with Monaca tools (CLI, Monaca IDE - cloud-based IDE for Cordova, Localkit - desktop GUI).

JUniversal and Onsen UI can be categorized as "Cross-Platform Mobile Development" tools.

Some of the features offered by JUniversal are:

• OAuth (based on Scribe)
• JSON
• Unit testing (JUnit)

On the other hand, Onsen UI provides the following key features:

• Open source HTML5 hybrid app framework for PhoneGap & Cordova
• JavaScript framework agnostic
• Mobile-optimized HTML5, CSS and JavaScript with Web components

JUniversal and Onsen UI are both open source tools. Onsen UI with 7.5K GitHub stars and 869 forks on GitHub appears to be more popular than JUniversal with 132 GitHub stars and 22 GitHub forks.