Document Writer lets you edit a document in WYSIWYM manner (what you see is what you mean), similarly to LyX. It allows simple structuring of the document, so you can split your work to chapters, add addresses, affiliations, abstract, table of contents and index, insert pictures, tables and math equations and much more. At any time, document can be exported (published) to a professional-quality PDF file using LaTeX.
The main goal of the project is to create an application with simple but useful features for editing documents, a facility which is still missing in elementary OS. This is not intended to be a full-blown application for designing all kinds of layout possible. Instead, it focuses on simplicity and beauty of design.