browser incompatibility is the biggest issue (if not the only issue). this is almost a non-issue if you're just writing node related programs. but if you need t

browser incompatibility is the biggest issue (if not the only issue). this is almost a non-issue if you're just writing node related programs. but if you need to support in the browser, now you have edge, chrome, firefox, and safari at minimum. then some have to continue supporting ie10/ie11, or even worse, ie7+. don't forget about mobile devices, with ios having such a difficult-to-write-anything-new version of mobile safari. i'm writing a new app for myself, so i don't have to worry about any backwards compatibility issues, except it needs to work on my iphone, which uses mobile safari webviews, which means i have to either use shims or restrict myself back to es5, non-html5 features (or work around their html5 limitations). example: you cannot cache audio files to play using <audio> tags in mobile safari. safari just refetches it from your server (also has to recreate the audio object, which causes a lag in the audio being played). technically you _can_ cache if you convert all your audio files to base64 and use the webaudio api. i'm probably going to have to go this route because i'd like the app to be offline usable. so rather than spend time on my app, i now have to write out a build step for converting audio to base64. then test that it works fine in ios and desktop browsers (at least chrome, firefox). it all just keeps adding up.