First, make sure you have a java development kit installed, if not, fetch it from OpenJDK or from Oracle. Note that a Java Runtime does not suffice.
Now get a servlet container. Use, for example, the traditional Apache Tomcat or other web-application container. Make sure you spot the webapps directory.
Download the web-application from the snapshot and install the web-application. With tomcat, this can be done by unzipping the .war file, then putting the produced EmailQuestionnaire directory into the webapps directory and restarting. Adjust the home page (at EmailQuestionnaire/index.jsp) to suit your needs in case that page is visited.
By default, servlet-containers are accessible over the port 8080 which is rather not something one wishes to advertise. A simple way to expose EmailQuestionnaire within traditional URLs is to insert a proxy directive inside Apache configs (either httpd.conf or .htaccess) such as the following ProxyPass /EmailQuestionnaire http://localhost:8080/EmailQuestionnaire This will forward all requests with path /EmailQuestionnaire to the web application container.
Moreover, if you want to configure the web-application container to last long, you should configure that it start everytime the machine restarts. This is best done by the servlet-container (e.g. as a Windows Service or Linux Daemon).
Edit the file web.xml inside the WEB-INF directory of the EmailQuestionnaire web application so that the received data, stored as XML files, are written in a correct place.
You are now ready to create an HTML questionnaire. See the How-to-create-an-email-questionnaire.