Crosswalk vs J2ObjC: What are the differences?

What is Crosswalk? Replace Android’s default WebView with Crosswalk, a predictable web runtime for developing powerful Android and Cordova apps. Crosswalk is a web runtime for ambitious HTML5 applications. All the features of a modern browser, deep device integration and an API for adding native extensions.

What is J2ObjC? Java to iOS Objective-C translation tool and runtime used by Google Inbox to share 70% of its code across Android, iOS, and Web. J2ObjC is an open-source command-line tool from Google that translates Java code to Objective-C for the iOS (iPhone/iPad) platform. This tool enables Java code to be part of an iOS application's build, as no editing of the generated files is necessary. The goal is to write an app's non-UI code (such as data access, or application logic) in Java, which is then shared by web apps (using GWT), Android apps, and iOS apps.

Crosswalk and J2ObjC can be primarily classified as "Cross-Platform Mobile Development" tools.

Crosswalk and J2ObjC are both open source tools. J2ObjC with 5.47K GitHub stars and 771 forks on GitHub appears to be more popular than Crosswalk with 2.17K GitHub stars and 569 GitHub forks.