You Don't Know GIF – An analysis of a GIF file and some weird GIF features
>Now the first line ends like this which is still a perfectly valid gif. How might that look?<p>>Amazing! Stupendous! Wonderful! As of the time of this writing, it’s just a perfectly black square. And this is the case in every single renderer I’ve tried. Gimp, Chrome, Firefox, Preview, gifiddle, you name it.<p>Funnily enough in my browser (Firefox on Ubuntu) it's transparent, but it's level of transparency I have never seen before - I can see the window below.