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Yes. Tomcat itself is validated to the extent it can be. Tomcat implements two several Java Specifications: EE Specifications, most important of them are the Servlet Specification and the Java Server Pages (JSP) Specification. Each of these specifications has a Technology Compatbility Compatibility Kit (TCK), which is a collection of tests to certify a given product meets the Specification fully and accurately.
The Apache Software Foundation is licensed to run these TCKs. They are run against every single major Tomcat release. No Tomcat release is pronounced stable unless it has passed both of these TCKs with 100% compliance. Therefore, every stable Tomcat release is validated to the extent of Tomcat's core functionality.
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