The Modern Language Association citation format for Internet sources (which the MLA refers to as "Web publications") varies depending on the type of source. Because they change frequently, MLA style does not require URLs for Web publications.
Owl.English.edu recommends the following format for Web publications in MLA citations: "Editor, author or compiler name (if available). Name of Site (italicized). Version number. Name of institution/organization affiliated with the site (sponsor or publisher), date of resource creation (if available). Medium of publication. Date of access."
Use "n.p." to indicate that there is no publisher name available and "n.d." for no publishing date.