The generic Web interface of Saada is based on Java servlets. A servlet is a Java object executed by the web server on client request (a kind of Java CGI - sorry for the purists). The servlet must be run by specific Web servers. The 2 most known (in the Linux/Unx world at least) are j2ee by Sun and Tomcat by the Apache fundation. Both are free, work very well and can be used by Saada. However we advise to use Tomcat.