Your terminology is inaccurate/wrong. Most coins are forks of bitcoin, not "built on top of". If you don't know what a fork is, i suggest you learn about Free Software. Most of this cryptocurrency stufff is built using Free Software, even if you wouldn't know it based on all the catering to corps, banks and slaveware platforms(windows, mac).
Your terminology is inaccurate/wrong. Most coins are forks of bitcoin, not "built on top of". If you don't know what a fork is, i suggest you learn about Free Software. Most of this cryptocurrency stufff is built using Free Software, even if you wouldn't know it based on all the catering to corps, banks and slaveware platforms(windows, mac).