XFree86 and X11R6

> What is X11R6? and what is XFree86? so far i know, xfree86 is the x[color=blue]
> window server, am i correct?[/color]

X11 is a protocol which is used to communicate from the X clients to the X
server. X11R6 means that this is the sixth release of this protocol (before
that were X10 which is not compatible to X11). The RFC 1013 describes this X
Window System protocol (i.e. X11).

XFree86 provides an implementation of this protocol, as does X.org. That
means that it provides the X server. But it provides also some other
programs (the window manager twm, for example). The sources are based on the
MIT sources where X11 was developed.

The english Wikipedia article states: "In computing, the X Window System
(commonly X11 or X) is a networking and display protocol which provides
windowing on bitmap displays."

Regards,
Sebastian