Calligra Words is an application that uses the text (flake) shape to show text-based documents with arbitairy page sizes and it can do a lot of DTP-like functionality due to the featureset that Flake brings. Since the main text layout and rendering core is moved into a flake plugin this can be used by any Calligra application and thus most of the Words functionality is available across all apps.

How this is done is to use the KoText library to contain the text loading code and various interfaces (APIs) for using text in an application. Most of the functionality is kept out of the KoText library to keep it small to link to and the real code all lives in the text shape (which can be found in the plugins dir).

Here are some pages with more details and design documents;

Text engine restructuring

Calligra/Words/Layout restructuring To do list
Calligra/Text_Layout_R4 Some thoughts on how the final step should be done

Current Design Explanation

Calligra/Words/Tutorials List of tutorials relating to ODF and Words
Calligra/Words/Tables The tables in Words are based on Qt tables, here is how Qt tables work at the low low level.
Calligra/Words/RequirementSpecifications/ChangeTracking Requirement specifications for Change tracking.
Calligra/Words/Outline
Calligra/Text Layout

User interface Design

Calligra/End_2010_Text_Styles_UI_IRC_Meeting A re-work of the text styles tree.

Usecases for new tech or 'in-development' stuff

Calligra/Words/Master Documents Explains how a master document can make life easier.
Calligra/Libs/KoText/Change tracking What do we want to do with Change Tracking then?
Calligra/Libs/KoText/Text Plugins Usecases for writing plugins for the text shape. And which technology to use.
Calligra/Words/Scripting Scratchpad for scripting. Nothing final, just designing at the moment. Input welcome.

End User Ready

In order to make Words end user ready we have to know who the end user is. Turns out that there are different definitions which give different answers. The full details can be found at Calligra/Words/EndUserReady/Personas

Bug processing

The Calligra Words bugs are first triaged and prioritized. Depending on interest from developers (often related to priority but not nessessarily so) the fixing will start. This can be anywhere from immidiately to several years later

Prioritization is based on being ready for a basic user like Susan or for a more specilized user like A.D.Vance.

Right now we have plenty to do to support Susan, so it's quite unlikely the advanced cases will have much interest, but this is open source, and everybody is free to do what they want, so you never know ;)