whoisdoctorwho.co.uk was an Earth-run website originally created by Clive. It had a photograph of the Ninth Doctor and asked to contact Clive if anyone had seen him. On 5 March 2005, Rose used search-wise.net to find the website and began emailing Clive about the Doctor. (TV: Rose)
Behind the scenes
Who is Doctor Who? (titled simply Doctor Who? in the search engine results in TV: Rose) is a real website that tied into series 1 of Doctor Who. It initially had simply the Ninth Doctor photograph and a "sightings" page, which during the active life of the site contained a web form with which users could submit their own "sightings" of the Doctor, under whichever name they wished. After a short delay (presumably time for vetting of the comments for suitability by the BBC's website operators), new sightings would be added to the page. Additional user-generated pages of this type were added for several episodes' updates to the site.
Amusingly, the basic purpose of the "sightings" page was essentially to allow the public to add events to the real-world version of a Doctor Who universe website.
After Clive's death in the story, Rose, Mickey Smith took over, writing fictional articles about various events, including the 2005 Auton invasion of London, the attempt by the family Slitheen to destroy the world and Guinivere One's flight to Mars, amongst others.
The site was renamed Defending the Earth! during series 2 and had missions for the readers of the website to help Mickey as he seemingly decided it was hard to do things all by himself, allowing the readers to help combat alien invasions.
Once Mickey was left in an alternate reality in The Age of Steel, a "David R" took over, the missions were replaced with games and a quiz was added to test the readers of the website about what David, Mickey, Clive, LINDA and various other groups had researched over the last few years. However, by the end of series 2, the website was no longer being updated.