About the data to be seen in play mode: which information of the game do you want to see at all times? Which information about your opponent? For instance, is it relevant to see the pieces taken, the history of last moves - or can these be retrieved through additional screens e.g. overlayed with some transparency?

Addison, chat might come later so we need to think a user interface for playing games without it.

Game score yes, Crafty can give you this but might be expensive in power manager. I still remember the fan of my laptop calculating those ratings N moves ahead. Perhaps better optional or even only in display mode. At the end... isn't a bit like cheating (o demoralizing) for normal game play?

Tapping to move, yes.

How modular should or could Miniature be? It would be nice to have a light core providing the minimum most players want: play chess online. And then provide the rest through additional modules or plugins.

Imagine this use case for the future: take a picture of a chess problem in the newspaper, get it processed thanks to and OCR module. Ready to be displayed in Miniature!

A couple of URLs found, just in case there is something interesting in there:

http://chessx.sourceforge.net/
a chess database. With ChessX you can operate on your collection of chess games in many ways: browse, edit, add, organize, analyze, etc.

http://chessratingcalc.sourceforge.net/
This is a free and open source calculator of chess rating for tournament players. It has features like saving calculation with details

http://ajonsson.kapsi.fi/cutechess.html
http://gitorious.org/cutechess