Developed by Ulrich Cordes, CPC4X is a basic emulator running under Linux/X11 with TCL/TK installed. Supports up to 576KB of memory and 7 ROM images loaded. It is also compatible with Vortex' XDOS.
While it can run most 'normal' software fine, it has problems loading and executing hardware-sensitive and 'tricky' games.
You can find its homepage here