emacs

Website: https://www.gnu.org/software/emacs/

Best for: code editing in the terminal

Strengths:

• Infinitely customizable
• Best in class plugins and extensions (many ideas start in emacs, and disseminate outwards)
• org mode
• Great git integration (magit)
• built-in email client

So powerful it is almost comparable to an operating system, emacs is an extremely powerful text editor that can be customized in code.