David Baron reminded me on IRC that there have been throbber design contests in the past…
There’s this Netscape page for a 1995 (?) animation contest (holy 16-color flashback, batman!), which conveniently has images for each frame for the winner and top 5 entries… APNG time!
(Update: Unfortunately due to a WordPress bug, the APNG images shown blow get converted to static images. Click on the images to get view the originals on dolske.net, where they should work properly. Sorry!)
Here’s the winner (left), and the final version that made it into Netscape:
And the 5 runners up:
There was also a second contest in 1999, but I can’t find the entries anywhere online… These two throbbers are in the old Mozilla 1.7 tree, perhaps they were the winners?
(I love that tile-flipping effect!)