Executor is a small but perfectly functional Java (1.5 or higher) JAR executable that is used to run programs in shared computer resources like a pool of computers that you and your friends own. Moreover, it can be used as a simple file sharing program: you can access the files of your home computer from your office computer. Executor uses a shared or synchronized file system. The user creates a task in one computer (just by uploading a file), and another computer that has the required program will execute the task.
SaluSafe is an encrypted email, chat, and file storage and sharing system. Your email and files are highly encrypted end-to-end, and cannot be intercepted by any third party. It was built from the ground up for security via strong cryptography, and is not just another security wrapper on top of an existing email solution.
PerlShare is a DropBox drop-in to create your own private file sharing "cloud". It consists of two parts; a client and a server. The server part lets you configure a Linux machine to accept PerlShare clients. PerlShare behaves a lot like DropBox. On collisions, for example, it creates conflicted copies. The workhorse for synchronization is Unison, a very reliable piece of software from Pascal Bach.
PeerProject is a versatile peer-to-peer filesharing client and file manager. It's intuitive and aesthetic while supporting many networks and features, including BitTorrent, G2, Gnutella, eDonkey, DC++, IRC, HTTP/FTP, and more. It's a mainstream fork of Shareaza p2p, for Windows and WINE.
Coquelicot is a “one-click” file sharing Web application with a focus on protecting users’ privacy. Its basic principle is that users can upload a file to the server, and in return they get a unique URL which can be shared with others in order to download the file. Coquelicot aims to protect, to some extent, users and system administrators from disclosure of the files exchanged from passive and not-so-active attackers.