ImageMapster started as a fork of David Lynch's MapHilight in early 2011. I wanted to add the ability to keep areas selected. I had a lot of ideas for interesting things that could be done with image maps, so ended up adding many more features. In the months since this began, I pretty much rewrote it from the ground up, but a few parts of the code, most notably the core VML rendering code, still inherit directly from its MapHilight roots.

I have put a great deal of effort into ensuring that ImageMapster will work reliably in many environments. Often, images will not be finished loading when the rest of a page has finished being configured. JavaScript code will usually begin running before some page images have finished loading. It is critical that images be completely loaded before ImageMapster can configure itself: it needs to know their native and display sizes, make copies, and do other work. The software uses a number of different methods, depending on the browser, to ensure that everything is ready when it begins configuration.

Additonally, ImageMapster will queue commands issued to it before configuration is complete. This means you can write post-configuration code that works against your image map without concern for the timing of images being loaded. Any commands that ImageMapster receives before it's done configuring will be queued, and processed in order once configuration is complete.

ImageMapster uses HTML5 canvases to do its work in modern browsers. In older browsers (Internet Explorer < 9) it uses VML to achieve similar effects.

ImageMapster works in all major browsers (Internet Explorer 6+, Firefox 2+, Opera, Chrome, and Safari) and on mobile devices.