License Choice
The Trajano organization has chosen Eclipse Public License as the license of choice for the products that are created.
The primary reason is it is acceptable by OSS guidelines in most enterprises and is vetted by many commercial vendors including IBM. Secondly it is a recognized open source license. See FAQ for Eclipse Public License for further answers.
However, some projects that are derived from other opensource projects will retain their respective license. e.g. Twentyfourteen Maven Skin uses GPL.