The Resin® high-performance, open source application server features load balancing for increased reliability. Caucho's QuercusTM is a fast, 100% Java implementation of the PHP language allowing developers to use PHP flexibility for the web interface and Java for stability.

Enhydra Server Enhydra Server is an Open Source Java application and webservice server including standard Apache Tomcat (or alternatively Jetty) and Apache Axis

JFox is an Open Source, standards-compliant, J2EE based application server implemented in 100% Pure Java, It comes from China Enterprise Open Source Community.

JOnAS is a leading edge Open Source implementation by OW2 of the Java EE specification. The stable versions are J2EE 1.4 certified. The License used by JOnAS is the LGPL.