Because when I firt read the documentation I saw packages, Interfaces... that Java programming langage...
So I just want to know what langage do I have to know to develop with Ext JS.
In 1 month I think I will buy a comercial licence. But It will be great if I can develope with the open source licence just for training.
My question is: If there is no diferencies in the langage between the tow licence?
Example: I firt develop this the open source licence and after I can develop just as the same way with the comercial licence.
There is no technical difference between the commercial and open source versions but make sure you do not deploy a public facing demo site before purchasing the commercial licence because some believe this will automatically open-source your internal project.