The program must include source code, and must allow distribution in source code as well as compiled form. Where some form of a product is not distributed with source code, there must be a well-publicized means of downloading the source code, without charge, via the Internet. The source code must be the preferred form in which a programmer would modify the program. Deliberately obfuscated source code is not allowed. Intermediate forms such as the output of a preprocessor or translator are not allowed.
Source code is a necessary preliminary for the repair or modification of a program.
The intent here is for source code to be distributed with the initial work, and all derived works. The license must allow modifications and derived works, and must allow them to be distributed under the same terms as the license of the original software. The intent here is for modification of any sort to be allowed. It must be allowed for a modified work to be distributed under the same license terms as the original work. However, it is not required that any producer of a derived work must use the same license terms, only that the option to do so be open to them.