is it open source ?
Doesn't look like it. http://appcenter.html5tools-software.intel.com/TOS/ Seems fairly permissive, but has provisions to do with de-compiling anything distributed in binary form so it looks fairly mixed. This may though just be due to use of some legacy, licensed library somewhere rather than deliberately restrictive licensing. I haven't looked closely at what comes with XDK so I'm not sure what components are used.
Intel, I won't be using it for my money making business. This corporate license thing is so 1990's.
Get with GPL alfaro. You will create way more wealth for the planet that way.