TextGlow was one of the first Silverlight 2.0 applications released and it showcased many of the new features and possibilities of Office Open XML and Silverlight.
The source code for TextGlow has been released along with an article published at OpenXML Developer, TextGlow - View Open XML Word documents with Silverlight. The article is a high level overview of the internals of TextGlow to help developers get started with their own applications.
I feel compelled to put in a disclaimer that the source code is somewhat… rough in certain places. I was the sole developer on the project and had just a couple of months to try and recreate as much as Word as possible. Fighting to keep what I had written against the constant stream of pre-MIX Silverlight 2.0 betas didn’t help either [:)]
You can find a link to the source code at the bottom of the article.