From the "about" page for the UD Dropbox service:
Email messages with large attachments can wreak havoc on email servers and your own system. Downloading such email messages can take hours on a slow Internet connection and block your sending and receiving of messages through the duration. In some cases, the download will fail repeatedly, breaking the recipient's ability to receive mail at all. Also, Internet email clients add considerably to the size of the file being sent. For example, saving an Outlook Express message with an attachment adds up to 40% to the file's size. If you want to share files larger than 1MB, use the UD Dropbox Service to temporarily make a file (or files) available to another user across the Internet, in a secure and efficient manner.
There are two distinct kinds of users that will be accessing the dropbox system: inside users, who are associated with the organization running the service, and outside users, which encompasses the rest of the Internet.
An inside user is allowed to create a drop-off that is to be delivered to anyone, whether he or she be an inside or outside user. An outside user is only allowed to create a drop-off that is to be delivered to an inside user. That begs the question: what is a drop-off?
The original variant of the dropbox service was PERL code that allowed a single file to be dropped-off to a single user. With version 2.0, a dropoff now can contain multiple files and can target multiple recipients. A 50 MB file to be delivered to five users need not be uploaded five times, and only one copy will be kept on the server. This increases efficiency both for the user and for the server (in terms of disk space, for example).
The code was written under the auspices of the University of Delaware (Network and Systems Services). It requires PHP 5 with at least support for SQLite (enabled by default when you ./configure). User authentication is handled via a chosen plugin – currently there exist LDAP and IMAP modules as well as a static, embedded username and password. Dropbox runs quite nicely through the Apache 2 web server with PHP support. Statistics tracking can be handled using RRDTool.
Version 2.2.0 of Dropbox is available for download. This version includes:
The ability to communicate a lengthy list of dropoff recipients by means of a CSV or text file was a feature request here at UD – who wants to click-and-type 30 email addresses, after all! The form referral service was also created to fill a department's need for a simple way of delivering potentially large files plus additional form fields.
This past weekend I added resumable download support to the UD production Dropbox. This basically required a modification to the
NSSDropoff::downloadFile() method to react to incoming
Range headers. The modification has been tested and works like a charm; look for it in the next release of Dropbox (which will happen sometime after the semester ends here at UD). Further discussion available (include browser support notes).