I’m a big user of GNU/Linux and Free Software, so I was at the origin of some of them, and I participate to the development of some free softwares too.
AlternC is a control panel for web and mail hosting server. With it, you can manage easily your hosting server for mail, websites, mailing-lists, statistics, jabber etc.
This project was born when hosting provider altern.org died in 1998. Since that time, it evolved to become an accessible and easy to use software, even by non computer-savvy users. My company, Octopuce, use it a lot …
It is also used by other hosting providers such as Koumbit or Neuronnexion, and many others we don’t even know of : AlternC is a free software, and as such, anybody can use it without any limitation !
It is currently distributed as a Debian package, and maintained by its users. It is multilingual (french, english, spanish as for now)
Document Manager (DManager)
The DManager is a free software of document management and sharing, which is bound to be as easy as possible, with simple access rights management: each account can be given read or write access to each folder. Therefore, you can share files easily through the web.
The interface of the Document Manager is very simple and multilingual (french, english, spanish as for now)