Payara vs Wildfly: What are the differences?
Payara: Recognized Leader in Creating Future-Proof Innovative Infrastructure Software. Payara Server is a drop in replacement for GlassFish Server Open Source Edition with quarterly releases containing enhancements, bug fixes and patches; Wildfly: A Java EE8 Application Server. It is a flexible, lightweight, managed application runtime that helps you build amazing applications. It supports the latest standards for web development.
Payara and Wildfly can be primarily classified as "Web Servers" tools.
Payara is an open source tool with 699 GitHub stars and 213 GitHub forks. Here's a link to Payara's open source repository on GitHub.