Open Source License
Concrete CMS is offered under the MIT open source license. In human:
Do whatever you want, but don't sue us.
The MIT License
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
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. 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.
Data Sharing from within the CMS
Concrete CMS is free and open source and can be run on just about any server you'd like. Unless you change its source code (which you're welcome to do) your copy of Concrete will periodically contact our servers to see if there's a new version available and get some news from the community. When that call back happens, we do track some information about your site and store that on our servers. This helps us know what versions of Concrete are in use and helps us develop a roadmap of features to serve your needs in the future.
If we detect you are using Concrete, we might use your logo on our marketing site. If you notice this and don't want us to, just ask.