X31

X31 is a designation used in several domains to label products, vehicles, or projects. The most notable uses occur in computing and aviation, where the name has been assigned to distinct programs or products.

ThinkPad X31: In 2003 IBM introduced the ThinkPad X31, a portable business laptop in the ThinkPad X-series. It was designed for mobility and durability and later continued in Lenovo’s lineup after the IBM PC division was sold. The X31 solidified the X-series’ reputation for compact, business-oriented laptops with a balance of light weight and robust construction.

X-31 (Enhanced Fighter Maneuverability Demonstration): The X-31, formally the X-31 Enhanced Fighter Maneuverability Demonstration aircraft, was an experimental program conducted by the United States, Germany, and related partners during the 1990s. The aircraft explored advanced flight-control systems and thrust-vectoring to improve maneuverability and handling. Findings from the program helped advance concepts in digital flight control and influenced later aircraft design and control-law development.

Other uses: As a general alphanumeric designation, X31 appears as a model or part number in various products across industries, including electronics and mechanical components. These uses are typically separate from the high-profile ThinkPad and X-31 programs and reflect the common practice of reusing short codes for multiple, unrelated products.