They have been around for a while, esp. about 10-20 years ago -- I've seen these plug-ins wane in popularity. I think the reason is the same as the arguments h

They have been around for a while, esp. about 10-20 years ago -- I've seen these plug-ins wane in popularity. I think the reason is the same as the arguments here for VP -- although a flowchart is nice in principal it becomes unwieldy and quickly looses any value once something doesn't all fit on the screen -- now your "navigating" rather than reading -- there is no gestalt to grok.