For a long time, people have made the claim that Christopher Marlowe was the actual author of Shakespeare's works or that he was a collaborator on the plays. Through research from a team of twenty-three academics (involving five countries) who used computerized textual analysis, it has been confirmed as of October 2016 that Marlowe collaborated with Shakespeare on the making of all three Henry VI plays. The New Oxford Shakespeare will be giving credit to Marlowe as a co-author on each of the plays' title pages.

The New Oxford Shakespeare's editors decision to include Marlow as a co-author of the Henry VI plays may lead to other attributions. There are possibly fourteen other Shakespearean plays that may have co-authors. Some of these co-authors may have made revisions to Shakespeare's original plays when they were published years later. An example of this is Shakespeare's work All's Well That Ends Well, in which Thomas Middleton made additions to the play before the printed publication. Middleton is officially credited now on the play's title page.

This textual analysis is done through the examination of "author-plus words." These are words that are generally commonplace, but a specific author tends to use them more in their works than other authors writing in the same era. Five of the Shakespeare-plus words that were identified are "gentle," "answer," "beseech," "spoke," and "tonight." With digital tools like textual analysis, researchers hope to continue to identify collaborations in Shakespeare's works, as well as works that Shakespeare contributed to but which were previously identified as anonymous. However, due to the loss of so many works from that era, researchers recognize that all collaborators may not be identified.