While at Lehigh, working with Doug Price and Steve Lidie, Cheswick co-authored the Senator line-oriented text editor.
In 1998, Cheswick, still at Bell Labs (by then controlled by Lucent) started the Internet Mapping Project, assisted by Hal Burch.
The research allowed large scale mapping of the internet for the first time, using tracerouting techniques to learn the connectivity graph of global networks.
The work ultimately led to the founding in 2000 of a spinoff company, Lumeta, where Cheswick was a co-founder and held the title of Chief Scientist.
His home is a farmhouse in Flemington, New Jersey, which is an electronic smart house, equipped with a voice synthesizer that reports relevant information, from mailbox status to evening stock news.