Thank you for downloading Confluence 4.1 - Standalone distribution. This distribution comes with a built-in Tomcat 6.0.32 web server and hsql database, so it runs (almost) out the box.
A known startup problem is when another program has claimed a configured network port 8090, which Confluence is configured to run on by default. To avoid this port conflict, use the installer which checks for conflicts during installation. Otherwise Confluence's port can be changed in conf/server.xml.
Thank you for using Confluence!
- The Atlassian Team