Gnoppix was an operating system primarily intended to offer the GNOME desktop environment on a Live CD, which allows the operating system to be used without installing it to hard disk.
Gnoppix was inspired by Knoppix, a Live CD distribution which used KDE for its user interface until the version 6 release. Both distributions are based on Advanced Packaging Tool, designed for Debian. The name is a play on Knoppix but with a G, in the tradition of naming GNOME apps with an initial G (to KDE's K). (Knoppix now uses LXDE and the new initial LX[clarify].)
Although Gnoppix was intended to be used as a Live CD, it could also be installed to and booted from a hard disk. Gnoppix was originally built around its own customised Live CD environment; The Main developer, Andreas Mueller was hired by Canonical to continue his work at Ubuntu.