Dictionary.com, an online dictionary, was founded in 1998 by Brian Kariger and Daniel Fierro, as part of Lexico Publishing, which also included Thesaurus.com and Reference.com. The content for the site is based on the Random House Unabridged Dictionary, with other content from the Collins English Dictionary, American Heritage Dictionary and others. In 2008, Dictionary.com was acquired by Ask.com, an IAC company.