I do not include easter eggs in production code, since if an application does not work properly or has a bug because of an easter egg, the consequences may be unpredictable due to a code the customer never asked for ...
Not all easter eggs are seen by customers. I often hid small images and little tricks that required a certain set of operations to be performed. Thankfully I worked at a company that was relatively good about it.
Some that the public could see:
1) April Fools day - icon would go upside down
2) Halloween - icon would turn into a pumpkin
3) XMAS - like VLC, you see a Santa hat on the icon
4) In one product, double clicking on the About dialog would show a picture of us
5) "Sex, Drugs and Rock & Roll" shown in the help file
The best one:
We had a data analysis program that would display "Your calculations are doo-doo" under certain instances when the data set was malformed. One customer called us up about it and I immediately knew who put it in. Thankfully one customer ever saw that but at least he got a good laugh out of it.
"Computer games don't affect kids; I mean if Pac-Man affected us as kids, we'd all be running around in darkened rooms, munching magic pills and listening to repetitive electronic music."
Maybe, 10 years ago, I would say "Sure, that would be fun". Nowadays, with the rise of cybersecurity awareness and concern, this behavior might raised the eyebrow of the customer. Imagine if you can embed Coded Easter Eggs for fun into a production code, what else can you or did you do to raise hell?
I always wonder, what if the independence QA person found it, how would they report this issue??
...but they are **very** well hidden and not for the public. In many cases they contain secret "Developer Modes" to enable some additional settings (like Developer Settings on Android Phones where you tap 10 times the OS Version tag).
These are features like switching the webspace where the app accesses its data - so we can test new content from a dev webspace directly out of the app without having to run a special "developer" version of the app. Some of the customers make their dynamic content for themselves and some power users get a manual, how to activate that mode.
Pure Fun-Eastereggs? Not really - in a game eventually but not in a business app.
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