What third party libraries are in the Platform and what are their licenses?
You can find the information about NetBeans code license at http://netbeans.org/about/legal/index.html.
Matrix of third-party libraries can be found in Third Party License link for the particular version at http://netbeans.org/about/legal/product-licences.html.
Note that if your application depends not only on Platform (modules from 'platform' cluster) but also on other parts of the NetBeans IDE (e.g. modules from the 'ide', or 'java' clusters) there may be derived dependencies on other 3rd party libraries.