In a wave of recent open sourcing occurring over the past weeks including Google, Facebook, Apple and IBM, Watson joins this effort to attract creative minds to its API. I saw IBM Watson demo at RSNA 2015 and it blew me away. The demo showed a large saddle pulmonary embolism on a CTA. What appeared to be computer aided image retrieval and automated data abstraction from medical records including symptoms and d-dimer, it generated probabilities of top differential diagnosis.... Very cool.