Cryptonote is a cryptocurrency like Bitcoin, Ethereum, etc.
Many coins like Dash, PIVX are forked from Bitcoin but Cryptonote has a completely different codebase like Ethereum.
Cryptonote is very convenient to fork; it’s official Readme explains that method in detail.
There are several cryptocurrencies which are forked from Cryptonote like Monero, which is 9th ranking on coinmarketcap
