Produced by Boston-based IDG World Expo, Macworld Conference & Expo is a trade show dedicated to the Apple Macintosh platform with conference tracks held annually in the United States, usually during the second week of January. Macworld is the most widely read Macintosh magazine in North America, and is a trademark of its publisher Mac Publishing, a wholly owned subsidiary of International Data Group. IDG World Expo is also a subsidiary of International Data Group. At one time, the show was known simply as Macworld Expo.
The Conference & Expo features educational conferences taught by leaders in their field, which require large admission fees to attend, and last for a few more days than the Expo. The Expo is open for a number of days (generally three or four), and attendees can visit the exhibits set up by hardware manufacturers and software publishers that support the Macintosh platform.
Until 2005 the show was held biannually, with an additional summer show held in the Eastern U.S.

Culture
There was some discussion among critics about the necessity of having two Macworld events (referring to the San Francisco expo and the now-defunct New York/Boston summer expo) in the United States at a time when non-Mac focused events such as COMDEX were encountering financial trouble. Additionally, as Apple continues to expand its retail presence in the U.S. market, some have speculated that the need for an annual gathering of Mac enthusiasts has been reduced. (Apple seems to encourage this thinking by favorably comparing, on numerous occasions, the volume of visitors appearing in Apple retail stores to the number of attendees at Macworld Expo.) The emergence of the World Wide Web has also contributed to the decline in trade shows of relatively established markets such as the Macintosh business. Nevertheless, Macworld Expo is still one of the largest technology trade shows in the United States, as well as San Francisco's largest single trade show.