appserver.io is described as 'Multithreaded application server for php written in php. Our technology allows real multi-threading in PHP and different useful services for developers enabling more efficiency and security. And best of all – it is completely open source!' and is an app in the development category. There are nine alternatives to appserver.io for a variety of platforms, including Linux, Mac, Windows, Self-Hosted and Docker apps. The best appserver.io alternative is TrailBase, which is both free and Open Source. Other great apps like appserver.io are Glassfish, FrankenPHP, JBoss and Mako Server.