Apps with 'Split windows' feature
Terminator, multiple terminals in one window. The goal of this project is to produce a useful tool for arranging terminals.
DisplayFusion will make your multi-monitor life much easier. With powerful features like Multi-Monitor Taskbars, TitleBar Buttons and fully customizable Functions, DisplayFusion will make managing your multiple monitors painless.
iTerm2 is a replacement for Terminal and the successor to iTerm. It works on Macs with macOS 10.10 or newer.
Chocolat is a new text editor for Mac OS X, that combines native Cocoa with powerful text editing tools.
QT-based multitab terminal emulator.
SplitView enables dual monitor usage with Remote Desktop and widescreen monitors.