Actipro SyntaxEditor for WPF's first public beta is now live (http://www.actiprosoftware.com/Products/DotNet/WPF/SyntaxEditor/Default.aspx). It has a very feature-rich base framework that we've put months of development time into based on our years of experience in this area. More features will be added soon but in the meantime check out the 40+ samples we offer. Works in XBAPs too!
