What was the code name for Internet Explorer 1.0?

The code name for Internet Explorer 1.0 was O'Hare.

Internet Explorer 1 first shipped in 1995 as part of Microsoft Plus! for Windows 95. It was based on technology Microsoft obtained from Spyglass and was initially a small, basic browser compared with later releases.

The name O'Hare connected Internet Explorer to Windows 95's Chicago code name: O'Hare International Airport is located in Chicago. Microsoft described the connection as a point of departure from Chicago to distant places.

A common mix-up is Chicago, which was the code name associated with Windows 95 itself, not Internet Explorer 1. Daytona and Memphis were also Microsoft code names used for other products or projects.