When comparing Slap vs Howl, the Slant community recommends Howl for most people. In the question“What are the best programming text editors?” Howl is ranked 21st while Slap is ranked 47th. The most important reason people chose Howl is:
You don't need the mouse to use Howl. Everything can be accomplished with commands and shortcuts.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro First-class mouse support
Slap supports mouse keybindings even though it works inside the terminal and also through SSH.
Pro Uses desktop-like keybindings
Slap features configurable keybindings (Ctrl+S, Ctrl+Z, etc).
Pro Great terminal interface
Pro Keyboard driven
You don't need the mouse to use Howl. Everything can be accomplished with commands and shortcuts.
Pro Fast startup
It's extremely lightweight, making it start up pretty quickly.
Pro Easy to use
Howl is very intuitive and easy to use.
Pro Easy to extend
Plugins (bundles) can be written in Lua or MoonScript.
Pro UI Focused on editting
Non distracted icons, toolbars, pannels, extra spacing, etc.
Pro Language tooling
Has built-in functionality for completion, inline documentation and linting so IDE-like features can be added easily.
Pro Command line palette
Search for your commands in an easy way and see in the list which key-strokes are mapped to which commands
Pro Open source
Howl is an open source project and is actively developed on GitHub(howl-editor/howl). It has a MIT license.
Pro Works on OpenBSD
Cons
Con Requires node.js
Slap is written in JavaScript and it requires something to interpret it in a local machine. That something is node.js, but for people who don't need node, it would be a hindrance and an overkill to install node just to use a simple text editor. Furthermore, it can only be used remotely if the remote machine has node installed.
Con CLI only
Slap only runs through the terminal.
Con Lack of Lua examples
Although Howl can be extended in both Lua and MoonScript, almost all bundles are written in MoonScript. This means that it is a bit harder to find examples if you'd rather write your bundle in Lua. MoonScript can be compiled to Lua but the code won't be as clean and understandable as if it would've been written in Lua by hand.