How compatible are tomcat 6 and websphere 6x? We develop against tomcat because it's picky enough that if our apps run in tomcat we have little if any trouble running them in a production environment with websphere. Is that still a safe assumption, or what do we need to be aware of?
Tomcat is the reference implementation of the servlet and JSP specs. This means that, in theory, if it works in Tomcat it should work in any other spec compliant container.