Whisk is described as 'Tumult Whisk is the lightweight HTML and PHP editor with a live preview pane that displays the updated page as you type. It is an essential app for your web dev toolkit' and is an app in the Development category. There are more than 50 alternatives to Whisk for a variety of platforms, including Windows, Linux, Mac, Online / Web-based and BSD. The best alternative is Visual Studio Code, which is free. Other great apps like Whisk are Notepad++ (Free, Open Source), Atom (Free, Open Source), Sublime Text (Free Personal) and Vim (Free, Open Source).
VS 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.
Neovim is a project that seeks to aggressively refactor Vim in order to: Simplify maintenance and encourage contributions. Split the work between multiple developers. Enable the implementation of new/modern user interfaces without any modifications to the core source.