Text editor

Visual Studio Code (also known as VSCode) is, in my opinion, the best IDE software available.

Font

I use Fira Code, which is actually a Google Font, but there's an awesome ligatured version available on GitHub, which is what I use.

Colour Theme

I use Material Theme Palenight High Contrast which is part of the Material Theme package.

Icons

I use the Seti icon set which ships with VSCode.

Extensions

Browser

As a developer, I use Google Chrome. It can be a bit heavy on RAM, but its set of devtools are far superior to anything else available. If you're looking for something more visually extensible (and some great tab management features) Vivaldi is fantastic. If you're privacy-conscious, Brave is also a great alternative.

Terminal

I use iTerm2 with zsh and oh-my-zsh installed. I highly recommend this setup, and there's a fantastic tutorial here that will guide you through it.