Copyright - License
Curl and libcurl are true Open Source/Free Software and meet all definitions as such. It means that you are free to modify and redistribute all contents of the curl distributed archives. You may also freely use curl and libcurl in your commercial projects.
Curl and libcurl are licensed under a MIT/X derivate license, see below.
There are other computer-related projects using the name curl as well. For details, check out our position on the curl name issue.
The curl license
COPYRIGHT AND PERMISSION NOTICE
Copyright (c) 1996 - 2017, Daniel Stenberg, firstname.lastname@example.org, and many contributors, see the THANKS file.
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.