can open HTML, RTF, docx and plain text documents, while RadPdfViewer
can be used to preview PDF files. However, there is no Telerik control which can open all of these file formats.
This is so because PDF is a format for fixed documents and is not normally associated with text editors, but with text viewers. The functionality which is expected from a document editor and a viewer is quite different, so there will not be many benefits from combining the functionality of the two controls.
I hope this answers your question.
All the best,
the Telerik team