PuTTY - Popular free terminal application. Mostly used as an SSH client.
Sass - Syntatically Awesome Style Sheets
MobaXterm - Enhanced terminal for Windows with X11 server, tabbed SSH client, network tools and much more
PostCSS - Increase code readability. Add vendor prefixes to CSS rules using values from Can I Use. Autoprefixer will use the data based on current browser popularity and property support to apply prefixes for you.
iTerm2 - A terminal emulator for macOS that does amazing things.
Stylus - EXPRESSIVE, DYNAMIC, ROBUST CSS