C4
The first C4 conference was a two-day event held at the University Center in downtown Chicago. It was held on October 20 and October 21, 2006, with an optional trip to Adler Planetarium's TimeSpace show for attendees on October 22. Due to that year's Chicago Marathon, attendees unable to stay downtown were provided free passes to the Chicago 'L' railway system for the weekend (an arrangement referred to as "Plan 'L'").
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