More people entered the labor force, and not all were able to find jobs right away. Bad weather may have been a factor
Consumers like curation—stories that narrow the choices down to the best two or three
With yet another tweak to the health-care law, the Obama administration is heading off a popular Republican attack
Music executives are tapping services such as Shazam and Spotify to help predict tomorrow’s next big hits
In the five years since the most recent bottom, the stock market has very nearly tripled
Arunachalam Muruganantham, aka "Menstrual Man," designed simple devices that allow rural Indian women to make their own sanitary pads
The company's dubbing of storms with Greek and Latin names began in 2012 to help 'personalize' extreme weather
European MBA programs compete with top-tier U.S. schools for the best students at home and abroad
Organizations offer special training for senior entrepreneurs
By Douglas MacMillan
Twitter hasn't made a penny—but that's not stopping a whole class of entrepreneurs from trying to build their own businesses on the back of the microblogging pioneer. Twitter makes its code available to outside developers who in turn can create their own tools that sort, analyze, distribute, append ads to, or otherwise interact with the millions of 140-character messages posted to Twitter each day.
From Twitter browsers to ad networks and multimedia tools, third-party programmers have dreamed up dozens of original ways to experience Twitter—and to make money from it. This BusinessWeek slide show tunnels through the many layers of the new Twitter ecosystem.