LICENSE-MIXING
上传用户:coffee44
上传日期:2018-10-23
资源大小:12304k
文件大小:6k
- License Mixing with apps, libcurl and Third Party Libraries
- ===========================================================
- libcurl can be built to use a fair amount of various third party libraries,
- libraries that are written and provided by other parties that are distributed
- using their own licenses. Even libcurl itself contains code that may cause
- problems to some. This document attempts to describe what licenses libcurl and
- the other libraries use and what possible dilemmas linking and mixing them all
- can lead to for end users.
- I am not a lawyer and this is not legal advice!
- One common dilemma is that GPL[1]-licensed code is not allowed to be linked
- with code licensed under the Original BSD license (with the announcement
- clause). You may still build your own copies that use them all, but
- distributing them as binaries would be to violate the GPL license - unless you
- accompany your license with an exception[2]. This particular problem was
- addressed when the Modified BSD license was created, which does not have the
- announcement clause that collides with GPL.
- libcurl http://curl.haxx.se/docs/copyright.html
- Uses an MIT (or Modified BSD)-style license that is as liberal as
- possible. Some of the source files that deal with KRB4 have Original
- BSD-style announce-clause licenses. You may not distribute binaries
- with krb4-enabled libcurl that also link with GPL-licensed code!
- OpenSSL http://www.openssl.org/source/license.html
- (May be used for SSL/TLS support) Uses an Original BSD-style license
- with an announcement clause that makes it "incompatible" with GPL. You
- are not allowed to ship binaries that link with OpenSSL that includes
- GPL code (unless that specific GPL code includes an exception for
- OpenSSL - a habit that is growing more and more common). If OpenSSL's
- licensing is a problem for you, consider using GnuTLS or yassl
- instead.
- GnuTLS http://www.gnutls.org/
- (May be used for SSL/TLS support) Uses the LGPL[3] license. If this is
- a problem for you, consider using OpenSSL instead. Also note that
- GnuTLS itself depends on and uses other libs (libgcrypt and
- libgpg-error) and they too are LGPL- or GPL-licensed.
- yassl http://www.yassl.com/
- (May be used for SSL/TLS support) Uses the GPL[1] license. If this is
- a problem for you, consider using OpenSSL or GnuTLS instead.
- NSS http://www.mozilla.org/projects/security/pki/nss/
- (May be used for SSL/TLS support) Is covered by the MPL[4] license,
- the GPL[1] license and the LGPL[3] license. You may choose to license
- the code under MPL terms, GPL terms, or LGPL terms. These licenses
- grant you different permissions and impose different obligations. You
- should select the license that best meets your needs.
- c-ares http://daniel.haxx.se/projects/c-ares/license.html
- (Used for asynchronous name resolves) Uses an MIT license that is very
- liberal and imposes no restrictions on any other library or part you
- may link with.
- zlib http://www.gzip.org/zlib/zlib_license.html
- (Used for compressed Transfer-Encoding support) Uses an MIT-style
- license that shouldn't collide with any other library.
- krb4
- While nothing in particular says that a Kerberos4 library must use any
- particular license, the one I've tried and used successfully so far
- (kth-krb4) is partly Original BSD-licensed with the announcement
- clause. Some of the code in libcurl that is written to deal with
- Kerberos4 is Modified BSD-licensed.
- MIT Kerberos http://web.mit.edu/kerberos/www/dist/
- (May be used for GSS support) MIT licensed, that shouldn't collide
- with any other parts.
- Heimdal http://www.pdc.kth.se/heimdal/
- (May be used for GSS support) Heimdal is Original BSD licensed with
- the announcement clause.
- GNU GSS http://www.gnu.org/software/gss/
- (May be used for GSS support) GNU GSS is GPL licensed. Note that you
- may not distribute binary curl packages that uses this if you build
- curl to also link and use any Original BSD licensed libraries!
- fbopenssl
- (Used for SPNEGO support) Unclear license. Based on its name, I assume
- that it uses the OpenSSL license and thus shares the same issues as
- described for OpenSSL above.
- libidn http://josefsson.org/libidn/
- (Used for IDNA support) Uses the GNU Lesser General Public
- License [3]. LGPL is a variation of GPL with slightly less aggressive
- "copyleft". This license requires more requirements to be met when
- distributing binaries, see the license for details. Also note that if
- you distribute a binary that includes this library, you must also
- include the full LGPL license text. Please properly point out what
- parts of the distributed package that the license addresses.
- OpenLDAP http://www.openldap.org/software/release/license.html
- (Used for LDAP support) Uses a Modified BSD-style license. Since
- libcurl uses OpenLDAP as a shared library only, I have not heard of
- anyone that ships OpenLDAP linked with libcurl in an app.
- libssh2 http://www.libssh2.org/
- (Used for scp and sftp support) libssh2 uses a Modified BSD-style
- license.
- [1] = GPL - GNU General Public License: http://www.gnu.org/licenses/gpl.html
- [2] = http://www.fsf.org/licenses/gpl-faq.html#GPLIncompatibleLibs details on
- how to write such an exception to the GPL
- [3] = LGPL - GNU Lesser General Public License:
- http://www.gnu.org/licenses/lgpl.html
- [4] = MPL - Mozilla Public License:
- http://www.mozilla.org/MPL/