Complex sentence: One of the primary goals during Windows NT 3.5's development was to increase the speed of the operating system; as a result, the project was given the codename "Daytona" in reference to the Daytona International Speedway in Daytona Beach, Florida.
Split into simpler sentences: One of the primary goals during Windows NT 3.5 development was to improve the operating system's performance. As a result, the project was codenamed "Daytona" in reference to the Daytona International Speedway in Daytona Beach, Florida.