Some clarifications are in order: This site is not a competitor to codepen, jsfiddle, etc. It's main purpose is to allow play with programming languages you'd

Some clarifications are in order: This site is not a competitor to codepen, jsfiddle, etc. It's main purpose is to allow play with programming languages you'd otherwise have to install locally -- specifically, it's extremely helpful when browsing https://codegolf.stackexchange.com/ https://codegolf.stackexchange.com/ -- the author is a prolific and impressive contributor to that site. It's sad to see a simple, well-designed, free, open-source project embracing the values of the HN crowd ("The TIO web app is free of charge, ad-free, and doesn't use tracking cookies or third-party analytic scripts.") -- and the top comment, as well as many others, are essentially a nitpick about a bug that can be trivially fixed.