Howl is described as 'general purpose editor that aims to be both lightweight and fully customizable. It is built on top of the very fast LuaJIT runtime, and can be extended in either Lua or Moonscript. It has a minimalistic UI driven mainly by the keyboard' and is a Text Editor in the Development category. There are more than 100 alternatives to Howl for a variety of platforms, including Windows, Linux, Mac, BSD and Chrome OS. Most alternatives are Text and Code Editors. The best alternative is Visual Studio Code, which is free. Other great apps like Howl are Notepad++ (Free, Open Source), Atom (Free Personal, Open Source), Sublime Text (Free Personal) and Vim (Free, Open Source).
Visual Studio Code is more than just a code editor, it provides the tools and extensions to compile, debug, compare, refactor, and even manage code repositories all within a highly-customised development environment.
Zettlr is a supercharged markdown editor that combines many writing editor features and collect them in one application. It aims at speeding up your workflow and help you write without any interruptions.
The Kate project develops two main products: KatePart, the advanced editor component which is used in numerous KDE applications requiring a text editing component, and Kate, a MDI text editor application.