A few months back I released some MATLAB code I contributed to MATLAB central under GPL. But the Mathworks sent me the e-mail early May

Dear Aravind Seshadri,

Starting later this month, the MATLAB Central File Exchange will adopt the well-known and widely used open-source BSD License as the standard license for posted content. As a File Exchange contributor, you are receiving notice of this new policy in advance of its implementation. No action is required now. We'll contact you again when a FAQ list is available and you are able to update your existing files.

Adopting a standard license for the File Exchange will help eliminate confusion around things such as modification rights, redistribution rights, author liability, and support responsibility. The community's needs in these areas are well served by the BSD license. We need your help to make this happen.

Starting in mid-May, new File Exchange submissions will be licensed under the BSD license as a condition of upload. You may then assign a BSD license to your existing submissions. A simple form-based tool for you to convert your existing files will be available at the File Exchange.