Vega is a new browser-side visualization toolkit from Jeff Heer. Why?
Vega provides a higher-level visualization specification language on top of D3. By design, D3 will maintain an “expressivity advantage” and in many cases will be better suited for novel, highly interactive graphics. On the other hand, we hope that Vega will be convenient for a wide range of common yet customizable visualizations. Vega’s design builds on concepts we developed in both Protovis and D3, and is informed by multiple years of research at Stanford and our experiences building data-driven applications at Trifacta.
Still waiting for prefuse to rise from the grave and reclaim its rightful place in the visualization firmament.