My goal is to allow people to upload and download large files through their web browser with a simple user interface and user password/account management. Yousendit offers a service like what I am looking for, but it does not make sense to use their service if I already have a web server.
Is there an open source version of Yousendit that I can run on my own web server?
What is this type of software or service called? (calling it an FTP Server does not seem to fit)