And Priya? She never rebooted into Boot Camp again.

She could drag a file from her Mountain Lion desktop into that old Windows database window. The shared folders feature (powered by VMware’s over a virtual network) made it seamless.

Today, that legacy lives on in VMware Fusion 13, Apple Silicon support, and even alternatives like UTM. But if you ever find an old Intel Mac running Mountain Lion 10.8.5 with VMware Fusion 4.x, you’ll see a piece of history: the moment when running “another OS” stopped being a hack and became a standard feature of the professional Mac.

In the spring of 2012, a software developer named Priya faced a dilemma. She loved the sleek interface of her new MacBook Pro, but her client’s legacy project required a clunky Windows XP application that refused to die. She didn’t want to reboot into Boot Camp every hour. She needed a digital bridge.