Well I go way back, for me the first time it was PERL for web programming, that lovely write-only language. The biggest one though was Javascript when Netscape

Well I go way back, for me the first time it was PERL for web programming, that lovely write-only language. The biggest one though was Javascript when Netscape first invented it. Suddenly FE development went from HTML without even CSS to actual programming, and one could see the potential of the platform. Then ActionScript 2, which was the short lived phase of Flash where it evolved from a vector toy for making spinning logos into a JS-like language (they were in the ECMA committee and everything), but you could do all sort of crazy animation and sound too. Sadly ActionScript 3 and Flex ruined it all for me, turning Flash into Java. But it was fun while it lasted. Luckily by then JS was reborn thanks to jQuery et al, and the next "wow" moment were all the APIs known collectively as "HTML 5" - from WebAudio to WebSockets to Canvas etc. And finally ES6 / WebPack and React / Flux, finally we could break away from the MVC model that never sat well within a browser environment, and with a modern language to boost.