ZKLFKPDNHVSDVVHVDWFRPSLOHUVZULWWHQ
VLJQDWXUHRI7\&RRQ$SULO
7\&RRQ3UHVLGHQWRI9LFH
7KLV*HQHUDO3XEOLF/LFHQVHGRHVQRWSHUPLWLQFRUSRUDWLQJ\RXUSURJUDPLQWRSURSULHWDU\SURJUDPV,I\RXUSURJUDPLVDVXEURXWLQH OLEUDU\\RXPD\FRQVLGHULWPRUHXVHIXOWRSHUPLWOLQNLQJSURSULHWDU\DSSOLFDWLRQVZLWKWKHOLEUDU\,IWKLVLVZKDW\RXZDQWWRGRXVHWKH *18/HVVHU*HQHUDO3XEOLF/LFHQVHLQVWHDGRIWKLV/LFHQVH
- GNU LESSER GENERAL PUBLIC LICENSE
Version 2.1, February 1999
&RS\ULJKW&)UHH6RIWZDUH)RXQGDWLRQ,QF
)UDQNOLQ6WUHHW)LIWK)ORRU%RVWRQ0$86$
Everyone is permitted to copy and distribute verbatim copies
of this license document, but changing it is not allowed.
>7KLVLVWKHƂUVWUHOHDVHGYHUVLRQRIWKH/HVVHU*3/,WDOVRFRXQWVDVWKHVXFFHVVRURIWKH*18/LEUDU\3XEOLF/LFHQVHYHUVLRQ hence the version number 2.1.]
Preamble
7KHOLFHQVHVIRUPRVWVRIWZDUHDUHGHVLJQHGWRWDNHDZD\\RXUIUHHGRPWRVKDUHDQGFKDQJHLW%\FRQWUDVWWKH*18*HQHUDO3XEOLF /LFHQVHVDUHLQWHQGHGWRJXDUDQWHH\RXUIUHHGRPWRVKDUHDQGFKDQJHIUHHVRIWZDUHWRPDNHVXUHWKHVRIWZDUHLVIUHHIRUDOOLWVXVHUV
7KLV OLFHQVH WKH /HVVHU *HQHUDO 3XEOLF /LFHQVH DSSOLHV WR VRPH VSHFLDOO\ GHVLJQDWHG VRIWZDUH SDFNDJHVW\SLFDOO\ OLEUDULHVRI WKH)UHH6RIWZDUH)RXQGDWLRQDQGRWKHUDXWKRUVZKRGHFLGHWRXVHLW<RXFDQXVHLWWRREXWZHVXJJHVW\RXƂUVWWKLQNFDUHIXOO\ DERXWZKHWKHUWKLVOLFHQVHRUWKHRUGLQDU\*HQHUDO3XEOLF/LFHQVHLVWKHEHWWHUVWUDWHJ\WRXVHLQDQ\SDUWLFXODUFDVHEDVHGRQWKH explanations below.
:KHQZHVSHDNRIIUHHVRIWZDUHZHDUHUHIHUULQJWRIUHHGRPRIXVHQRWSULFH2XU*HQHUDO3XEOLF/LFHQVHVDUHGHVLJQHGWRPDNHVXUH WKDW\RXKDYHWKHIUHHGRPWRGLVWULEXWHFRSLHVRIIUHHVRIWZDUHDQGFKDUJHIRUWKLVVHUYLFHLI\RXZLVKWKDW\RXUHFHLYHVRXUFHFRGH RUFDQJHWLWLI\RXZDQWLWWKDW\RXFDQFKDQJHWKHVRIWZDUHDQGXVHSLHFHVRILWLQQHZIUHHSURJUDPVDQGWKDW\RXDUHLQIRUPHGWKDW you can do these things.
7RSURWHFW\RXUULJKWVZHQHHGWRPDNHUHVWULFWLRQVWKDWIRUELGGLVWULEXWRUVWRGHQ\\RXWKHVHULJKWVRUWRDVN\RXWRVXUUHQGHUWKHVH rights. These restrictions translate to certain responsibilities for you if you distribute copies of the library or if you modify it.
For example, if you distribute copies of the library, whether gratis or for a fee, you must give the recipients all the rights that we gave \RX<RXPXVWPDNHVXUHWKDWWKH\WRRUHFHLYHRUFDQJHWWKHVRXUFHFRGH,I\RXOLQNRWKHUFRGHZLWKWKHOLEUDU\\RXPXVWSURYLGH FRPSOHWHREMHFWƂOHVWRWKHUHFLSLHQWVVRWKDWWKH\FDQUHOLQNWKHPZLWKWKHOLEUDU\DIWHUPDNLQJFKDQJHVWRWKHOLEUDU\DQGUHFRPSLOLQJ LW$QG\RXPXVWVKRZWKHPWKHVHWHUPVVRWKH\NQRZWKHLUULJKWV
:HSURWHFW\RXUULJKWVZLWKDWZRVWHSPHWKRGZHFRS\ULJKWWKHOLEUDU\DQGZHRIIHU\RXWKLVOLFHQVHZKLFKJLYHV\RXOHJDO permission to copy, distribute and/or modify the library.
7RSURWHFWHDFKGLVWULEXWRUZHZDQWWRPDNHLWYHU\FOHDUWKDWWKHUHLVQRZDUUDQW\IRUWKHIUHHOLEUDU\$OVRLIWKHOLEUDU\LVPRGLƂHGE\ VRPHRQHHOVHDQGSDVVHGRQWKHUHFLSLHQWVVKRXOGNQRZWKDWZKDWWKH\KDYHLVQRWWKHRULJLQDOYHUVLRQVRWKDWWKHRULJLQDODXWKRUőV reputation will not be affected by problems that might be introduced by others.
)LQDOO\VRIWZDUHSDWHQWVSRVHDFRQVWDQWWKUHDWWRWKHH[LVWHQFHRIDQ\IUHHSURJUDP:HZLVKWRPDNHVXUHWKDWDFRPSDQ\FDQQRW effectively restrict the users of a free program by obtaining a restrictive license from a patent holder. Therefore, we insist that any patent license obtained for a version of the library must be consistent with the full freedom of use specified in this license.
0RVW*18VRIWZDUHLQFOXGLQJVRPHOLEUDULHVLVFRYHUHGE\WKHRUGLQDU\*18*HQHUDO3XEOLF/LFHQVH7KLVOLFHQVHWKH*18/HVVHU *HQHUDO3XEOLF/LFHQVHDSSOLHVWRFHUWDLQGHVLJQDWHGOLEUDULHVDQGLVTXLWHGLIIHUHQWIURPWKHRUGLQDU\*HQHUDO3XEOLF/LFHQVH:HXVH
WKLVOLFHQVHIRUFHUWDLQOLEUDULHVLQRUGHUWRSHUPLWOLQNLQJWKRVHOLEUDULHVLQWRQRQIUHHSURJUDPV
:KHQDSURJUDPLVOLQNHGZLWKDOLEUDU\ZKHWKHUVWDWLFDOO\RUXVLQJDVKDUHGOLEUDU\WKHFRPELQDWLRQRIWKHWZRLVOHJDOO\VSHDNLQJD FRPELQHGZRUNDGHULYDWLYHRIWKHRULJLQDOOLEUDU\7KHRUGLQDU\*HQHUDO3XEOLF/LFHQVHWKHUHIRUHSHUPLWVVXFKOLQNLQJRQO\LIWKHHQWLUH FRPELQDWLRQƂWVLWVFULWHULDRIIUHHGRP7KH/HVVHU*HQHUDO3XEOLF/LFHQVHSHUPLWVPRUHOD[FULWHULDIRUOLQNLQJRWKHUFRGHZLWKWKH library.
:HFDOOWKLVOLFHQVHWKHœ/HVVHUŔ*HQHUDO3XEOLF/LFHQVHEHFDXVHLWGRHV/HVVWRSURWHFWWKHXVHUőVIUHHGRPWKDQWKHRUGLQDU\*HQHUDO 3XEOLF /LFHQVH ,W DOVR SURYLGHV RWKHU IUHH VRIWZDUH GHYHORSHUV /HVV RI DQ DGYDQWDJH RYHU FRPSHWLQJ QRQIUHH SURJUDPV 7KHVH GLVDGYDQWDJHVDUHWKHUHDVRQZHXVHWKHRUGLQDU\*HQHUDO3XEOLF/LFHQVHIRUPDQ\OLEUDULHV+RZHYHUWKH/HVVHUOLFHQVHSURYLGHV advantages in certain special circumstances.
For example, on rare occasions, there may be a special need to encourage the widest possible use of a certain library, so that it EHFRPHVDGHIDFWRVWDQGDUG7RDFKLHYHWKLVQRQIUHHSURJUDPVPXVWEHDOORZHGWRXVHWKHOLEUDU\$PRUHIUHTXHQWFDVHLVWKDW DIUHHOLEUDU\GRHVWKHVDPHMREDVZLGHO\XVHGQRQIUHHOLEUDULHV,QWKLVFDVHWKHUHLVOLWWOHWRJDLQE\OLPLWLQJWKHIUHHOLEUDU\WRIUHH VRIWZDUHRQO\VRZHXVHWKH/HVVHU*HQHUDO3XEOLF/LFHQVH
,QRWKHUFDVHVSHUPLVVLRQWRXVHDSDUWLFXODUOLEUDU\LQQRQIUHHSURJUDPVHQDEOHVDJUHDWHUQXPEHURISHRSOHWRXVHDODUJHERG\RI IUHHVRIWZDUH)RUH[DPSOHSHUPLVVLRQWRXVHWKH*18&/LEUDU\LQQRQIUHHSURJUDPVHQDEOHVPDQ\PRUHSHRSOHWRXVHWKHZKROH