In the time of Windows 98 and XP, the Adobe photoshop and other many other software use to have easter egg in Help -> About screen. You open this dialog, press Ctrl + Alt + Shift + (Enter probably) and it use to roll credits very fast or show something else, jokes sometimes, or a different background animation. I distinctly remember it was more than just Adobe software that had these.

I use to try it in any tool tools I was playing around with (I use to try lots of software just to see what they do) and often found something here.

These stopped being a thing at some point and I eventually stopped looking for these.