If you are working with HaxeNME, you might have noticed that compiled JS/HTML5 applications do not necessary work same as other platforms. Or don't work at all. Or don't compile because of some uncommon unimplemented method that you've used.
And as code base is accumulating "tricks" by multiple contributors, it does not necessarily remain entirely stable.
For example, if you've decided to clear your BitmapData-based 640x480 buffer via BitmapData.fillRect, you are making a huge mistake - the function is not just doing this pixel-by-pixel, but also via ImageData API.
Overall, this article is dedicated to substituting Browser/Jeash part of NME by your own library in JS compilation.