He is the author of several editions of the Java in 21 Days and Java in 24 Hours series from SAMS Publishing and has written other books on Radio UserLand, Microsoft FrontPage and the Internet. From 1982 to 1986, Cadenhead operated the Parallax BBS in Dallas, Texas, which was the first BBS to offer BBS door games.

He published the Internet humor site Cruel.com and is the copublisher of the community weblog SportsFilter. He has also been a contributor to Suck.com and previously authored a syndicated question-and-answer column called "Ask Ed Brice."

When conservative news aggregator Matt Drudge failed to register drudge.com for his news and gossip website Drudge Report, Cadenhead registered drudge.com in 1998 and started the Drudge Retort as a liberal alternative to the right-leaning Drudge Report, and as "a send-up of Mr. Drudge's breathless style". Cadenhead edits the site with television writer Jonathan Bourne. Both conservative and liberal bloggers utilize the open forum format, encouraged by Cadenhead. The headline selections for discussion are the liberal alternative to the Drudge Report.

Some readers may be confused between the two websites because the typography and page layouts are almost identical, and this is no coincidence since the site was deliberately designed to be like Drudge's website, using "the same style of type, the same rows of links to other journalists and columnists, the same screaming, sensational headlines trumpeting world exclusives". Cadenhead uses a yellow background, which implies that Drudge is a yellow journalist.

Even Matt Drudge visits the Drudge Retort, saying "I go there when I can't get into my own Web site because mine's so popular".

In 2005, Cadenhead achieved brief notoriety for registering the domain name benedictxvi.com several weeks before the name was chosen by Pope Benedict XVI, joking that he would give it to the Vatican in exchange for a mitre and "complete absolution, no questions asked, for the third week of March 1987." Those demands not being met, he donated the domain to the Internet charity Modest Needs.

In December 2005, Cadenhead again achieved significant blog and media coverage by highlighting that Wikipedia co-founder Jimmy Wales had edited his own Wikipedia article repeatedly, which Wales admitted was "in poor taste." [1] [2]

In June 2008, the Associated Press filed seven DMCA takedown requests against Cadenhead for stories published by users on the Drudge Retort reproducing from 39 to 79 words of AP articles. The action sparked a backlash among bloggers towards the news organization and a debate about what constitutes fair use when bloggers link and excerpt articles. "If The A.P. has concerns that go all the way down to one or two sentences of quoting, they need to tell people what they think is legal and where the boundaries are," Cadenhead told the New York Times. The affair led AP to change its policy and install new technologies to protect its work.