Paul Graham's blog: Curious choice of HTML for building the side panel

I was reading an essay on Paul Graham's blog[1] and the side panel[2] seemed erringly pixelated even on my MBP. I inspected the web page and found that the whole side panel is infact a gif[3] and the different links on the page are linked using the coordinates of the image.

Example for the first link:

TBH, I did not know this is something which can be done in HTML but that got me curious on how it ended up on PG's blog given many limitations it has :)

[1]: http://paulgraham.com/ [2]: https://i.imgur.com/uo254ts.png [3]: https://s.yimg.com/aah/paulgraham/quotes-1.gif

It's just old; back in the day HTML had very little graphic capabilities, and loading multiple images was comparatively slow (think 56k connections). So you'd load a single image and then subdivide that in clickable areas with image maps (which is what this is called).