Lots of mine (like git and vim) have already been mentioned, so here's some different ones
The Elm compiler, for giving me a welcoming on-ramp into functional programming. It's not the best nor my favourite, but its by far the most beginner friendly and is worth all developers learning for how it changes the way you think.
ed, whichever implementation you chose. And that's precisely what I'm thankful for. It showed me (via Michael W Lucas's book) that a software program can be fully specified, that you can have the entire spec in your head, and that you can just pick up any compliant implementation. So very refreshing.
The Elm compiler, for giving me a welcoming on-ramp into functional programming. It's not the best nor my favourite, but its by far the most beginner friendly and is worth all developers learning for how it changes the way you think.
ed, whichever implementation you chose. And that's precisely what I'm thankful for. It showed me (via Michael W Lucas's book) that a software program can be fully specified, that you can have the entire spec in your head, and that you can just pick up any compliant implementation. So very refreshing.