Purple Numbers refers to a suite of tools that allow addressing HTML content at the paragraph level. It was originally a concept of Douglas Engelbart for his creation of hypertext. They were implemented in PurpleWiki by Eugene Eric Kim and Chris Dent and called Purple Numbers. The tools got their name from the faint, purple numbers at the end of each paragraph, which represent the link to that paragraph. The name Purple Numbers was coined by Christina Engelbart, Doug's daughter.