Johnson, an American popular science author, launched online service in 2006 describing it as "an attempt to collectively build the geographic web, neighborhood by neighborhood".
, founded by Arianna Huffington, received backing from Palo Alto, California-based Oak Investment Partners in December to invest in technology and expand its content offering.
Huffington said at the time that she was planning to roll out local versions of The Huffington Post in select cities and it appears that the plan is going ahead.
She said in December: "This commitment from Oak Investment Partners will allow us to accelerate our growth, with more verticals, more video, more citizen journalism initiatives, more cities for our local editions, and a fund for investigative journalism."
The Huffington Post launched in May 2005 and currently includes sections devoted to politics, entertainment, media, living, business, and the green movement.
In addition to columns by Huffington, a core group of contributors and founding editor Roy Sekoff, the Huffington Post has also featured notable celebrity contributors from politics, journalism, business, and entertainment including Barack Obama, Hillary Clinton and John Cusack.
The site received a major traffic boost from its US presidential election blog.