Apache Tomcat is the servlet container that is used in the official Reference Implementation for the Java Servlet and JavaServer Pages technologies. Sun developed the Java Servlet and Java Server Pages specifications under the Java Community Process.
Apache Tomcat is developed in an open and participatory environment and released under the Apache Software License. Apache Tomcat powers numerous large-scale, mission-critical web applications across a diverse range of industries and organizations.
Apache Tomcat Versions:
For different versions of the Servlet and JSP specifications there are different versions of Apache Tomcat available. The mapping between the specifications and the respective Apache Tomcat verisons is:
Servlet/JSP Spec Apache Tomcat version
Alpha / Beta / Stable:
Initially every Tomcat release is released as an Alpha release. After a week, a vote is held to gather views on the stability of the release. If a major issue is identified during testing, then the vote may not take place and the release will remain as an Alpha release. Stability is a subjective judgement and you should always read carefully the release notes for any version you intend to make use of.
Alpha releases may contain large amounts of untested/missing functionality required by the specification and/or signifcant bugs and are not expected to run stably for any length of time.
Beta releases may contain some untested functionlaity and/or a number of relatively minor bugs. Beta releases are not expected to run stably.
Stable releases may contain a small number of relatively minor bugs. Stable releases are intended for production use and are expected to run stably for extended periods of time.