X11 for Mac OS X offers a complete X Window System implementation for running X11-based applications on Mac OS X. Based on the de facto-standard for X11, the open source XFree86 project, X11 for Mac OS X is compatible, fast and fully integrated with Mac OS X. It includes the full XFree86 4.4 distribution including a window server, libraries and basic utilities such as xterm.
X11 Never Looked So Good
Native Aqua and X11 applications run side by side on the Mac OS X desktop. You can cut and paste between X11 and Aqua windows. You can minimize X11 windows to the Dock even with the Genie Effect. You use the Aqua window controls to close, minimize and zoom X11 windows. And of course, each X11 window comes with its own carefully rendered drop shadow. Experts may choose to replace the native Aqua window manager with their own familiar, standard X Window Manager.
X11 for Mac OS X takes advantage of the Mac OS X Quartz graphics system to deliver hardware-accelerated 2D and 3D graphics. Quartz provides snappy scrolling speeds for text, live drag and resize of windows, as well as no-compromise 3D animation through OpenGL Direct Rendering.
Easy to Port X11 Applications
With the complete suite of the standard X11 display server software, client libraries and developer toolkits, X11 for Mac OS X makes it even simpler to port Linux and Unix applications to the Mac. X11 for Mac OS X gives you a complete, rootless X11R6.6 implementation, as well as display server and client libraries plus headers in the SDK. X11 for Mac OS X supports ssh tunnelling for secure display sharing. You can download all the common toolkits from OpenDarwin.org. Plus, Tiger inludes native support for popular toolkits such as Tcl/TK and W+widgets.