Decor

From the help, with introduction by Geoffery Khoo:

Automated backdrop changer for JPEGs and Sprites
Written for RISC OS 3.1 or higher (with SpriteExtend 0.99 and above), although may work on RISC OS 3.1 with SpriteExtend and Dynamic Area support

Décor is a small TSR program I saw on the Macintosh which allows you to change the "desktop pattern" or backdrop after a certain amount of time. I decided to write a version for RISC OS for fun.

Well, it's a backdrop changer for which is able to alter the RISC OS desktop backdrop after a predetermined amount of time. You can also change the backdrop manually if you get sick of the one that is already being displayed. The advantage of this backdrop changer of others I have seen is that it is able to directly process JPEG files, and so the lovely new backdrops you have downloaded from the Internet don't have to be converted into sprites. Also, it can re-plot the JPEG file upon mode changes so the grotty 256 colour mode which did your picture no justice can be shown in up to 16 million colours without you having to do anything!

History
Décor was written originally in BBC Basic by Geoffery Khoo, and later extended then converted to C by Peter Naulls. Most recently in October 2009, it has been re-released under the GPL, but has not had any code changes in over 6 years.

Download

 * Decor is available as RiscPkg package from riscos.info.

Source is included for native RISC OS building, and it can also be built from the RISC OS autobuilder.