Game Maker is Windows and Mac compatible. Here are the System Requirements.
Game Maker requires a Pentium PC running Windows 2000, XP, Vista, or later with at least 256MB RAM. Your system must also have a DirectX 8 (or later) compatible graphics card with at least 32MB of Video RAM. Screen resolution must be at least 800x600 and 65000 (16-bit) colors. You need to have DirectX 8 (or later) installed.
Minimum Requirements: Intel Mac, running Mac OS Leopard v10.5 or Snow Leopard v10.6.