NW.js (node-webkit) lets you call all Node.js modules directly from DOM and enables a new way of writing applications with all Web technologies. Developed by Roger Wang
License: Open Source
B4X is primarily focused on mobile app development, offering a user-friendly environment and integrated IDE, while NW.js excels in web and desktop application development using web technologies. Both platforms have strong community support and performance optimization, but B4X is more suited for mobile environments, whereas NW.js is ideal for web and cross-platform desktop applications.