How do I use this software? I downloaded it, but when I run it there's no GUI.
Fred (the Freenet REference Daemon) runs as a daemon, or service, in the background. You normally talk to it with a Freenet client. One of the services that Fred offers is called fproxy, which lets you talk to Freenet with a web browser. Point your web browser to
http://127.0.0.1:8888/ for the gateway page. Try clicking the various links in the "Bookmarks" panel to reach some of the popular Freenet index sites.
If you're looking for applications that run on top of Freenet and provide a different interface or functionality, please see the Tools page.