when i was in uni in 2014 i learned that smalltalk became obsolete, later i went to industry to see that no one use smalltalk(or prolog) and yet on this site ppl bringing up smalltalk every single month, why is that i wonder

Yeah there's a difference between being popular and influential. Smalltalk is influential without being all that popular.

I suspect that's largely because most smalltalk implementations don't store code in git. "A smalltalk" is more like a Linux distro than a phone app. It's almost like the main purpose of a smalltalk is to build more smalltalks. It's a good way for developers to build a deep, powerful tool for other developers, but it's a less good way to build user experiences targeted at non-programmers, who are going to want to have a bunch of different apps to use not a bunch of different operating systems to use.

Good economics for the classroom; bad economics for the real world. Then and now, though, a great way to play with novel ideas in programming languages.

The Potsdam university (near Berlin, Germany) and Hasno Platner Instute [1] has been actively teaching and researching Squeak Smalltalk for decades. Same in Buenos Aires and several other places. Science papers every month for 5 decades, under many names besides Smalltalk. Weekly online conferences, presentations.

https://www.hpi.uni-potsdam.de/hirschfeld/projects/index.htm...

People like the language - I like it though I have only written a few bits and bobs in it. They also like Fortran, Prolog, and (dare I say it) Haskell, and many others that don't appear here so often. Just because a language is not this week's hotness (looking at you Rust) does not make it "obsolete".

Likely because whilst it didn't work out commercially, the ideas smalltalk, prolog and other more esoteric languages (forth, apl) focus on are themselves very interesting.

A lot of systems are obsolete, in the sense that you cannot find work in them. Nonetheless, people use them to prototype ideas that will eventually find their way into industry. Is Haskell obsolete? Not exactly, but it's hard to find real-world projects that use it. Concepts developed in Haskell get imported into other systems.

Systems are only truly obsolete when there is no real reason to use them. PL/1 is obsolete. It's hard to find even legacy code using it, and nobody would use it for experimentation.

In what way, obsolete? There is quite a bit of worthwhile research done in Smalltalk-related languages and some corporations are quite successful in building on such languages.

It's not dominant in the way of Wordpress but also not insignificant.