Xoo
Xoo is a GTK+ based graphical wrapper around a ‘windowed’ X Server. It is intended for embedded developers that want to simulate a target device (with an accurate display resolution and colour depth, working hardware buttons, and so on) on a desktop machine.
The size of the embedded X server, and the image around it are themable by the user. The default theme is based on a Compaq iPaq 4700, and supports the hardware buttons. There is also a theme for the Nokia N800 Internet Tablet, and creating a new theme is as simple as writing a XML file.
The embedded X server can either be Xnest (XFree86/X.org) or Xephyr (KDrive). The advantage of using Xephyr is that it supports the newer X extensions such as Render, RandR, Composite, and Damage; allowing you to test applications using these extensions even if your native X server doesn’t. Xoo can also send a signal to Xephyr so that it will highlight the region it is painting, to help debug redraw problems.
Xoo is authored by Matthew Allum and Ross Burton. It is free software, available under the GPL.
Download
Xoo is maintained in Git, at http://cgit.freedesktop.org/xorg/app/xoo/.