[jbosstools-dev] tern.java vs VJET?

Hi JBoss guys, I have noticed that you had integrated VJET last year. I have never played with VJET, but I have seen features screenshot of VJET (like object litteral validation) and it seems very powerful. My goal is to try to implement the same feature than VJET, but I'm very curious why you decided to integrate and contribute to tern.java although you have VJET. Could you please give me pros, cons for using tern.java and VJET? Many thank's for your info. Regards Angelo