Debian-Lenny is the codename for Debian GNU/Linux version 5.0.
Debian GNU/Linux version 5.0 (codenamed Lenny) is a free operating system which supports a total of twelve processor architectures and includes the KDE, GNOME, Xfce, and LXDE desktop environments. It also features compatibility with the FHS v2.3 and software developed for version 3.2 of the LSB. As of Jan 3, 2012, the current stable Debian version is 6, or "Squeeze". Version 7, "Wheezy" is in active development.