iTerm2

iTerm2 is a modern, feature-rich terminal emulator for macOS. It extends and improves on the built-in Terminal app by offering advanced features like split panes, profiles, search, autocomplete, instant replay of terminal history, and much more. The repository contains the full source code (primarily in Objective-C / Swift) along with UI components, extensions, and support tools. It is released under the GPL-2.0 license. The project is quite mature (with many commits and contributors) and supports scripting and automation via an API (including a Python library in the api/library/python/iterm2 path). To build it, you can compile the Xcode project included, and there is documentation and instructions linked from the project’s README (note: issue tracking is handled via GitLab, as the repository refers issues there). The code is organized into modular parts (resources, UI, helpers, submodules), and the project is actively maintained with many releases and tags.