TotalFinder - TotalFinder is a plugin for Finder.app which adds tabs like in Chrome browser, dual panels similar to TotalCommander and more tweaks.
Alacritty - Alacritty is a blazing fast, GPU accelerated terminal emulator.
Path Finder - The Finder, reinvented. Path Finder is an award-winning file browser and management application for Mac OS X.
Xfce4 terminal - Productivity
Forklift - The most advanced dual pane file manager and file transfer client for macOS.
Terminology - Common uses of the term are, "html coding" and "html website". A website created in pure html is also referred to as a static website. In other words, it does not interact with the visitor other than in the most basic ways.