19.2 Legal restrictions of DJGPP utilities and libraries

Q: Can I redistribute djgpp, and if so, how?

Q: I run a business that sells shareware for distribution costs. Can I include djgpp on my CD-ROM?

Q: I want to include djgpp in a product that happens to need a compiler provided with it. Can I do this?

Q: Is DJGPP public domain software?

Q: Is DJGPP shareware?

A: DJGPP is not public domain, neither is it shareware (you don't have to pay a license fee to use DJGPP). Parts of DJGPP (the compiler and some of the development tools) are GNU software, so you must comply with GNU GPL if you distribute those parts (usually, you won't need to distribute them, because they are freely available to everyone). A small part of the C library is taken from the Berkeley BSD sources, and is therefore in public domain.

Other parts of DJGPP, which include most of the C library, the free DPMI host CWSDPMI, and some of the utilities, are copyrighted, but in a way that allows you to use them freely and without restrictions. The copyright that covers these parts of DJGPP is GPL (LGPL for the library), the GNU License, but with a special exception: if you distribute the utilities unmodified, or build programs with the unmodified library, GPL/LGPL does not apply.

Compliance with the Gnu license is therefore all you are legally required to consider when you redistribute DJGPP itself (as opposed to your programs compiled with DJGPP). However, based on many years of experience of DJGPP distribution, DJ Delorie requests vendors which distribute DJGPP to follow some additional rules. These rules are generally meant to provide a better service to the DJGPP user community:

• You must redistribute DJGPP as a whole, with all its parts, including the sources to utilities and libraries that are part of DJGPP, unless other arrangements are first made with DJ Delorie.
• Please make a good faith effort to stay up to date with the latest DJGPP versions, so people don't get old versions with bugs that are long ago solved, or, worse still, versions that are no longer supported.
• You must call it DJGPP and nothing else.
• You may not take credit for it, and you must not remove any notices in DJGPP that give credit to those who worked on it.
• You must tell the recipient how to get the latest version off the Internet, or at least how to find out what the latest version is. DJ Delorie gets a lot of questions from people who got old versions from vendors and don't realize that they're way out of date.

In addition, it would be a courtesy to inform DJ that you are including DJGPP in your product, in case this information is obsolete. A token sample of your distribution would be nice also.

Note that the above are not legal restrictions (the latter are described in the file copying.dj mentioned in the previous section), they are recommended guidelines for redistributing DJGPP. These guidelines are based on many years of experience and are generally meant to make it easier for your clients to use DJGPP and get support from its developers. Vendors who do not follow these guidelines could risk public humiliation, verbal abuse, and boycott by the DJGPP community, but not legal action.

Note also that if you make source-level changes to DJGPP library or utilities, the changed software falls under the GNU License, GPL/LGPL, unless these changes are made to fix bugs, and provided that you also submit all such bug-fixes to DJ Delorie for inclusion in a future DJGPP release.