GroupOffice is a groupware suite that takes your office online, implementing online collaboration and CRM. It allows you to share projects, calendars, files and email online with co-workers and clients. It is easy to use and fully customizable. It also features synchronization with PDAs and Outlook.
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.
Image Tools is a screen capture and file sharing tool. It features multi-threaded batch image resizing, conversion, cropping, flipping/rotating, watermarks, decolorizing (grayscale, negative, sepia), and optimizing. The BMP, GIF, TIFF, JPEG, PNG, and EMF image types are supported. It is compatible with MONO (only for GNOME). Multicore processing is supported to increase performance. The quality for output when optimizing is variable. Color channels can be filtered. An internal benchmarking tool is available. Indexed pixel format images can be processed.
uhub is a high performance peer-to-peer hub for the ADC network. Its low memory footprint allows it to handle several thousand users on high-end servers, or a small private hub on embedded hardware. It uses the ADC protocol, and is compatible with DC++, jUCy, and other ADC clients.