Today I learned that the default RichTextBox control does not handle hyperlinks out of the box. If you do want to have hyperlinks work, you need to do the following: 

• DetectUrls property on the RichTextBox control is set to True
  
  
• Open the Designer.cs file and find the generated code block for the RichTextBlock properties and handlers. Add the following line:
  
  this.myRichTextBox.LinkClicked +=
    new LinkClickedEventHandler (this.myRichTextBox_LinkClicked);
• Add the eventhandler to the .cs file:
  
  private void myRichTextBox_LinkClicked(object sender, LinkClickedEventArgs e) {
    System.Diagnostics.Process.Start(e.LinkText);
  }

That is it...