Windows XP Professional x64 Edition is an operating system developed by Microsoft as an extended version of the Windows XP family, specifically designed to support 64-bit computing. It was released on April 25, 2005, and aimed to take advantage of the increased memory and processing power available in 64-bit systems.

Key Features of Windows XP Professional x64 Edition:

1. 64-bit Architecture: The primary feature of this edition is its support for 64-bit processors, allowing it to address larger amounts of memory and perform more complex calculations.

2. Compatibility with 32-bit Software: While designed for 64-bit computing, Windows XP Professional x64 Edition also provided support for running 32-bit applications through its Windows-on-Windows 64-bit (WOW64) compatibility layer.

3. Enhanced Performance: With its 64-bit architecture, the operating system could handle larger datasets and run applications more efficiently, especially those designed to take advantage of 64-bit processing capabilities.

4. Security Improvements: Similar to its 32-bit counterpart, Windows XP Professional x64 Edition included security features like Windows Firewall, Data Execution Prevention (DEP), and improved encryption to help protect against various threats.

5. Driver Support: Initially, one of the challenges with the x64 edition was driver compatibility. However, over time, more hardware manufacturers began to provide 64-bit drivers, improving hardware support for this edition.

6. Server Capabilities: While not as feature-rich as Windows Server editions, the x64 Edition could serve as a lightweight server for specific tasks, benefiting from its 64-bit architecture.