Building Docxion: An Open-Source Office Document Viewer for Android and the Web Viewing a PDF inside an application is relatively straightforward. Viewing Microsoft Office documents is a different story. DOC, DOCX, XLS, XLSX, PPT, and PPTX all come with their own rendering challenges. If you want users to open these documents directly inside your application, you quickly end up choosing between complicated rendering stacks, external applications, proprietary SDKs, or solutions with lic...