I could not get web applications – in this case JasperServer, but I’m sure it applies to anything – placed in /usr/share/tomcat6/webapps/ to autodeploy, and was therefore getting 404 errors. I am not sure if this is because of the Tomcat install which comes with Ubuntu (which is notoriously bad, although I thought these issues had been resolved?).
The JasperServer install guide is excellent, but at the end it (correctly) assumes the autodeploy will work, and that browsing to http://localhost:8080/jasperserver/ will bring up the login page.
To get around this issue, copy /usr/share/tomcat6/webapps/jasperserver/META-INF/context.xml to /etc/tomcat6/Catalina/localhost/jasperserver.xml and restart Tomcat.
Tomcat Version: 6.0.20
Ubuntu Version: 9.0.4