JBoss is a division of Red Hat that provides support for the WildFly open source application server program and related middleware services. JBoss is an open source alternative to commercial offerings from IBM WebSphere and SAP NetWeaver that is used for implementing Java applications and other Web-based applications and software. It runs on Java Virtual Machine (JVM) versions and is a Java EE application server with a built-in Apache Tomcat 5.5 servlet shell. It also supports many operating systems, including Portable Operating System Interface for Unix (POSIX) platforms, GNU/Linux, Free Berkeley Software Distribution (FreeBSD), Mac OS X, Microsoft Windows, and other JVM-compliant machines.