Mac app that shows all open files, directories, sockets, pipes and devices in use by all running processes. Nice GUI for lsof.

A window management application (replacement for Divvy/SizeUp/ShiftIt)

A lightweight macOS window and app manager scriptable with JavaScript

Desktop WebKit wrapper for HTML/CSS/JS applications.

Cocoa framework for updating OS X apps

The MacOS X kernel extension, preventing sleep when you close the lid.

Simple app that archives (and restores) Safari's currently-open windows+tabs