Neovim is an open-source and cross-platform development software and application that helps developers increase their productivity by providing powerful editing features. It is a modern, feature-rich text editor that is designed to be highly extensible. It provides an intuitive, keyboard-driven interface for developers to work with code quickly and efficiently. Neovim supports a variety of programming languages and allows developers to customize their development environment to fit their individual needs. It also includes built-in debugging and syntax highlighting capabilities to help developers quickly identify and fix errors in their code. Neovim is an ideal choice for developers who need a fast, reliable and extensible development environment.
Both are powerful text editors that allow a great deal of customization.
Discontinued Appears to be abandoned. The last release was January 2016
Very light and still usable. It sits between vim and nano. It also has a more common link that you might be used to from other programs (ctrl-c to copy, ctrl-v to paste, ctrl-s to save, etc.).
Discontinued The developers announced that development of TextWrangler was halted, in favor of concentrating their efforts on developing BBEdit. Quoted on the TextWrangler website, "We are running TextWrangler, and encourage anyone interested in TextWrangler to download and use BBEdit instead."
If you use GUI (graphics, not terminals) this is the best alternative.