:title: FAQ
:description: Most frequently asked questions.
:keywords: faq, questions, documentation, docker

FAQ
===


Most frequently asked questions.
--------------------------------

1. **How much does Docker cost?**

   Docker is 100% free, it is open source, so you can use it without paying.

2. **What open source license are you using?**

   We are using the Apache License Version 2.0, see it here: https://github.com/dotcloud/docker/blob/master/LICENSE

3. **Does Docker run on Mac OS X or Windows?**

   Not at this time, Docker currently only runs on Linux, but you can use VirtualBox to run Docker in a
   virtual machine on your box, and get the best of both worlds. Check out the :ref:`install_using_vagrant` and :ref:`windows` installation guides.

4. **How do containers compare to virtual machines?**

   They are complementary. VMs are best used to allocate chunks of hardware resources. Containers operate at the process level, which makes them very lightweight and perfect as a unit of software delivery.

5. **Can I help by adding some questions and answers?**

   Definitely! You can fork `the repo`_ and edit the documentation sources.


42. **Where can I find more answers?**

    You can find more answers on:

    * `Docker club mailinglist`_
    * `IRC, docker on freenode`_
    * `Github`_
    * `Ask questions on Stackoverflow`_
    * `Join the conversation on Twitter`_


    .. _Docker club mailinglist: https://groups.google.com/d/forum/docker-club
    .. _the repo: http://www.github.com/dotcloud/docker
    .. _IRC, docker on freenode: irc://chat.freenode.net#docker
    .. _Github: http://www.github.com/dotcloud/docker
    .. _Ask questions on Stackoverflow: http://stackoverflow.com/search?q=docker
    .. _Join the conversation on Twitter: http://twitter.com/getdocker


Looking for something else to read? Checkout the :ref:`hello_world` example.