These are Ethereum ERC20 Token Smart Contracts, and there is another half to it, TRON TRC20 Token. The TRC20 is Free to make, and allows you to copy and part your ERC20 Solidity contracts into TronScan with just a few changes like your wallet address. TRON copied UniSwap and made JustSwap.
So, TRON and ETH are the main platforms, and there are currently several places to list your ERC20 Tokens on a DEX manually, but the ERC20 bar to entry is a little higher since it is not Free.
ERC20 is not only more expensive to create, but also much more expensive to use and there is no way for token owner to pay fees for its users which is possible in TRON.