Please note that GroupDocs.Viewer for .NET is a back-end API that can be integrated in any (new or existing) .NET application without any third party tool or software dependency.
Yes, you can. Please have a look at these helpful threads:
As we explained earlier, GroupDocs.Viewer for .NET is a back-end API that could be integrated in any .NET application without any dependency. All you have to do is to add this DLL reference in your WPF application.
Please note that the API does not directly displays the documents. Instead, it renders the document as HTML pages or images and then you can display the rendered (HTML or Image) pages in your application. You may have a look at the following articles to know how documents are being rendered by the API: