In order to sustain and grow the public good of free education and free culture, everyone who contributes content to Serlo projects has to grant the public free use of this content, as long as in this use the attributions of the contents to the original authors, and the freedom for further use of all derived content is maintained. Following this reason you agree that by saving content on serlo.org of which you hold the copyright, it will come under the license http://creativecommons.org/licenses/by-sa/4.0/. The “Serlo Education e. V.” reserves the right to put all content on www.serlo.org (and all subpages as well as other language-tenants) under another free license, or a newer version of the currently used free license, that also supports the public good of free education and free culture and is equivalent to the conditions of the currently used free license,. The author agrees with such license-changes at the discretion of Serlo Education e.V.. After a license change the use of the content is also following the new license regulations.
As contributor to the platform you agree that you will not have to be referenced. You agree that you will not create or publish abusive, obscene, insulting, defamatory, or otherwise criminal content on serlo.org and to, when using serlo.org, follow the legal regulations of your country, the country in which the website is provided from, as well as supranational and international law. A violation of these rules can lead to ban.
Content that you found in other places or that you created together with other collaborators can only be imported by you, if it is available under conditions compatible with the CC-BY-SA-license. That means only content which is available under conditions compatible to the CC-BY-SA-license, or content that besides other licenses (like the GNU Free Documentation License) is also available under compatible conditions to the CC-BY-SA-license, can be imported.
You can freely take the content from Serlo-services for further use, except the content that has to be used in other conditions of copyright (see below). Please follow the following rules: http://creativecommons.org/licenses/by-sa/4.0/
Exercises and content that is provided under a license other than http://creativecommons.org/licenses/by-sa/4.0/ will be indicated as such below the content or, in editing mode, in the spoiler element titled “license” to the right of the content.
If any individual provision of this Agreement or the application thereof should be found invalid or void now or in the future, the remaining provisions will remain in full force and effect and shall in no way be affected, impaired or invalidated thereby. If found invalid or void, any clause of this contract will be replaced by an economically equitable substitute provision to effect the original intent of the faulty provision. Such a substitute provision will be negotiated and agreed upon by both parties in good faith.