This is cool but using rectangles instead of circles would help this visualization. Circles waste real estate and not friendly to labels (e.g. curved text that is harder to read)
But big picture, this write-up isn't tied to the current visualization! It's more focused on exploring _how_ a visual representation could help our understanding of codebases. There are tons of jumping off points, including different vizes!
This would be great for a presentation where I'm trying to make our codebase look flashy and cool. But for actually getting work done, I'll take a tree map any day. Check out the mac app GrandPerspective if you haven't seen it - great use of tree maps for cleaning up hard drive space.