What was the greatest achievement / product / evolution / … for you in your programming history?

I remember we got CSS. I didn't understand then why we would need that, because I did everything with image maps 😂. Back then we all called it DHTML, as in Dynamic. Can you imagine js was just some handy thing tucked away somewhere in the browser with which one could create some basic interaction? Haha, 🤔 whaddayamean ajax??

But I would choose the invention of Docker as the greatest thing that happened to me in dev life 🚀. Suddenly I could have completely separated environments with all sorts of services on my local machine, by just running some simple commands! And then have that exact environment on the server also!

I had spent so many hours debugging in the "doesn't work on production" category, trying to get my local xampp php version the same as the one on client 1 vps, then again for all n customers and all their different envsironments. Docker changed my life.