Office 365 is a suite of products from Microsoft that introduces a new software "rental" model rather than the traditional perpetual license model. The name "Office 365" therefore refers to a licensing model rather than a specific version of Microsoft Office. Most versions of Office 365 include the full Office Desktop Suite, including Microsoft Word.

eXtyles works as a Word add-in to the Office Desktop Suite. eXtyles fully supports Office 365 when you have purchased a version that includes the full Office Desktop Suite (e.g., Office 365 Business, Office 365 Business Premium, Office 365 Home) and you have installed the full Office Desktop Suite on a traditional Windows laptop or desktop PC. eXtyles does not support mobile versions of Office running on a tablet or smart phone.