This slide puzzle is able to solve itself. The algorithm is developed and programmed by Jerry Brons in June 1997 as a project assignment for the PSO2 (programming and software engineering) course that is part of Jerry's education to electro-technical engineer at the Rijswijk Institute of Technologies. Jerry did this project with two other students Menno Andriesse and Jim-Roy Grippeling. This project required 20 hours of work for each of them.
This project assignment was formulated a year earlier by Sidney Huiskamp, Saskia Kriek, Jacob Jan van der Steur and Friso de Wolf. They created a graphical Windows 3.1 version that was not able to solve itself and was not very stable. (But what can you do in only 20 hours each?)
Jerry, Menno and Jim-Roy started out with an non graphical DOS version that was able to solve itself. They tried to integrate their program with the Windows 3.1 program that was developed a year earlier. It worked but was not very stable. (But what can you do in only 20 hours each?)
The course leader Harry Broeders developed in a free weekend in October 1997 a completely new graphical Windows 3.1 slide puzzle and used Jerry's algorithm to let the puzzle solve itself.
Jerry who was working (as part of his education) with Harry on a programming project for the NATO NC3A at that time liked the program and they decided to place it on the web. The map of Europe we used in the slide puzzle is a result of Jerry's NATO NC3A project. Each color represents a different height. Harry spent most of his autumn holidays finishing the program and writing these WWW pages.
In his christmas holidays Harry ported the main parts of the program to Java. This Java version was posted to the net in January 1998.
In October 1999 Harry ported the program to Win32. This new version (2.0) works better for windows 95/98/NT.
In July 2001 Harry added 3 more pictures to the free demo version (3.0).
In January 2006 Harry ported the program from Borland C++ 5.02 to the GNU gcc C++ compiler using the open source C++ GUI framework wxWidgets and the free IDE wx-Devcpp. 15 Puzzle version 4.0 is now able to open all sorts of graphical files and is available for free!