Mach3 is a computer-aided manufacturing (CAM) software that enables users to control CNC machines, routers, and other devices. The software allows users to create, edit, and execute G-code files, which are used to instruct the machine on how to perform various tasks, such as cutting, drilling, or engraving. Mach3 supports a wide range of devices and is compatible with various operating systems, including Windows.

The shop owner, an old man with a kind smile, noticed Alex's interest and approached them. "Ah, you've found the MACH3," he said. "That's a rare system, developed by a team of engineers who wanted to push the limits of computing." The old man leaned in, a conspiratorial look on his face. "They say it has some... unique features, hidden away for those who know where to look."