Data visualization startup Plot.io has been making some noise lately. From what I know so far, it looks a lot like Tableau, but presumably works in the browser. This could be a potential successor to Swivel, which folded a bit over a year ago, and maybe what Verifiable was trying to do.
Their teaser video is a bit confusing, but what it shows is an interface that looks a lot like Tableau. On their Twitter feed, they also talk about marks, and they seem to be aware of what is going on in the visualization community. They’re certainly worth watching.