Downloader is a program for downloading a website and saving it on the local filesystem. It was written as a homework assignment, and I doubt it's all that useful.
To run Downloader from the command line, execute scala -classpath bin DownloaderMain <url>. A file chooser will pop up, allowing you to select a directory to store the downloaded files.
To quit the downloader, just type "q" or "Q" at any time (you don't have to wait for the downloader to finish).