Hello, community. I looking for desktop wallet for Bitcoin and altcoins with open source code. Most popular wallets do not have open source code. Maybe there are alternative less popular software that allow to understand how it built.
What?
I don't think there's an altcoin that doesn't release its source code!
I think you mean that you have looked only at exchange sites and seen you cannot access how they work as that is how they are designed, otherwise you could manipulate them (unless you use inspect page source).
If you look at something like bitcoin.org and look at the source code for their wallet, it's even on github as github.com/bitcoin/bitcoin where you can access the source code which as far as I recall is either in C or C++.