======================================================================== * README ======================================================================== _ _ ____ _ ___| | | | _ \| | / __| | | | |_) | | | (__| |_| | _ <| |___ \___|\___/|_| \_\_____| README Curl is a command line tool for transferring data specified with URL syntax. Find out how to use curl by reading the curl.1 man page or the MANUAL document. Find out how to install Curl by reading the INSTALL document. libcurl is the library curl is using to do its job. It is readily available to be used by your software. Read the libcurl.3 man page to learn how! You find answers to the most frequent questions we get in the FAQ document. Study the COPYING file for distribution terms and similar. If you distribute curl binaries or other binaries that involve libcurl, you might enjoy the LICENSE-MIXING document. CONTACT If you have problems, questions, ideas or suggestions, please contact us by posting to a suitable mailing list. See http://curl.haxx.se/mail/ All contributors to the project are listed in the THANKS document. WEB SITE Visit the curl web site for the latest news and downloads: http://curl.haxx.se/ GIT To download the very latest source off the GIT server do this: git clone git://github.com/bagder/curl.git (you'll get a directory named curl created, filled with the source code) NOTICE Curl contains pieces of source code that is Copyright (c) 1998, 1999 Kungliga Tekniska Högskolan. This notice is included here to comply with the distribution terms. ======================================================================== * COPYING ======================================================================== COPYRIGHT AND PERMISSION NOTICE Copyright (c) 1996 - 2013, Daniel Stenberg, . All rights reserved. Permission to use, copy, modify, and distribute this software for any purpose with or without fee is hereby granted, provided that the above copyright notice and this permission notice appear in all copies. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. Except as contained in this notice, the name of a copyright holder shall not be used in advertising or otherwise to promote the sale, use or other dealings in this Software without prior written authorization of the copyright holder. ======================================================================== * docs/LICENSE-MIXING ======================================================================== 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. axTLS http://axtls.sourceforge.net/ (May be used for SSL/TLS support) Uses a Modified BSD-style license. 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/