The oldest stuff I use regularly at work would be Bash, Java, and Groovy. And then one specific utility stands out as something I use a lot, despite its age: se

The oldest stuff I use regularly at work would be Bash, Java, and Groovy. And then one specific utility stands out as something I use a lot, despite its age: sed. I use sed all over the place in scripts to inject values into config files as part of scripts.