| NETHACK GENERAL PUBLIC LICENSE |
| (Copyright 1989 M. Stephenson) |
| (Based on the BISON general public license, copyright 1988 Richard M. |
| Stallman) |
| Everyone is permitted to copy and distribute verbatim copies of this |
| license, but changing it is not allowed. You can also use this wording |
| to make the terms for other programs. |
| The license agreements of most software companies keep you at the mercy |
| of those companies. By contrast, our general public license is intended |
| to give everyone the right to share NetHack. To make sure that you get |
| the rights we want you to have, we need to make restrictions that forbid |
| anyone to deny you these rights or to ask you to surrender the rights. |
| Hence this license agreement. |
| |
| Specifically, we want to make sure that you have the right to give away |
| copies of NetHack, that you receive source code or else can get it if |
| you want it, that you can change NetHack or use pieces of it in new free |
| programs, and that you know you can do these things. |
| |
| To make sure that everyone has such rights, we have to forbid you to |
| deprive anyone else of these rights. For example, if you distribute |
| copies of NetHack, you must give the recipients all the rights that you |
| have. You must make sure that they, too, receive or can get the source |
| code. And you must tell them their rights. |
| |
| Also, for our own protection, we must make certain that everyone finds |
| out that there is no warranty for NetHack. If NetHack is modified by |
| someone else and passed on, we want its recipients to know that what |
| they have is not what we distributed. |
| |
| Therefore we (Mike Stephenson and other holders of NetHack copyrights) |
| make the following terms which say what you must do to be allowed to |
| distribute or change NetHack. |
| |
| COPYING POLICIES |
| You may copy and distribute verbatim copies of NetHack source code as |
| you receive it, in any medium, provided that you keep intact the notices |
| on all files that refer to copyrights, to this License Agreement, and to |
| the absence of any warranty; and give any other recipients of the |
| NetHack program a copy of this License Agreement along with the program. |
| You may modify your copy or copies of NetHack or any portion of it, and |
| copy and distribute such modifications under the terms of Paragraph 1 |
| above (including distributing this License Agreement), provided that you |
| also do the following: |
| a) cause the modified files to carry prominent notices stating that you |
| changed the files and the date of any change; and |
| |
| b) cause the whole of any work that you distribute or publish, that in |
| whole or in part contains or is a derivative of NetHack or any part |
| thereof, to be licensed at no charge to all third parties on terms |
| identical to those contained in this License Agreement (except that you |
| may choose to grant more extensive warranty protection to some or all |
| third parties, at your option) |
| |
| c) You may charge a distribution fee for the physical act of |
| transferring a copy, and you may at your option offer warranty |
| protection in exchange for a fee. |
| |
| You may copy and distribute NetHack (or a portion or derivative of it, |
| under Paragraph 2) in object code or executable form under the terms of |
| Paragraphs 1 and 2 above provided that you also do one of the following: |
| a) accompany it with the complete machine-readable source code, which |
| must be distributed under the terms of Paragraphs 1 and 2 above; or, |
| |
| b) accompany it with full information as to how to obtain the complete |
| machine-readable source code from an appropriate archive site. (This |
| alternative is allowed only for noncommercial distribution.) |
| |
| For these purposes, complete source code means either the full source |
| distribution as originally released over Usenet or updated copies of the |
| files in this distribution used to create the object code or executable. |
| |
| |
| You may not copy, sublicense, distribute or transfer NetHack except as |
| expressly provided under this License Agreement. Any attempt otherwise |
| to copy, sublicense, distribute or transfer NetHack is void and your |
| rights to use the program under this License agreement shall be |
| automatically terminated. However, parties who have received computer |
| software programs from you with this License Agreement will not have |
| their licenses terminated so long as such parties remain in full |
| compliance. |
| Stated plainly: You are permitted to modify NetHack, or otherwise use |
| parts of NetHack, provided that you comply with the conditions specified |
| above; in particular, your modified NetHack or program containing parts |
| of NetHack must remain freely available as provided in this License |
| Agreement. In other words, go ahead and share NetHack, but don't try to |
| stop anyone else from sharing it farther. |