•         Custom license specific to the product

•         Sometimes allows free use for non-profit organizations

•         Sometimes allows free use for everyone

•         Usually prohibits reverse engineering

•         Usually prohibits redistribution

•         Rarely includes source code

•         May include all sorts of bizarre terms

GNU/General Public License (GPL)

•         You are free to do whatever you want with the source code (modify, redistribute, etc.)

•         But… any changes you make that you distribute must also be GPL

•         And… any code you distribute that uses GPL code must be available under GPL

•         Defeats “embrace and extend”

•         Often called “viral” by both friend and foe

GNU Lesser General Public License (LGPL)

•         Used to be called “Library GPL”

•         Non-LGPL code can use it without becoming LGPL (e.g. linking during compile)

•         Resulting combined executable is LGPL

•         Many people think this means that you can use LGPL Java libraries from non-LGPL code

•         Not clear whether that interpretation is correct

•         We are not your lawyers :)

BSD/Apache Licenses

•         You can freely use, modify, re-license, etc. as long as you maintain the copyright notices

•         You can include the code in a commercial product without releasing your source code

•         You can embrace and extend

•         Safest for corporate use