Looks like Apache Contributors may qualify for a free license: " WHO QUALIFIES
Our Open Source Licenses are available free to truly volunteers developing non-commercial open source software. You qualify for a free license if: - your open source project meets the Open Source definition<http://www.opensource.org/docs/osd> ; - you have a dedicated website and an active developer community supporting your project; - you do not perform any paid support, consulting or training services for your open source software; - you do not distribute paid versions of your open source software. If you provide paid services for your open source software or distribute paid versions of your open source software, a license may or may not be granted to you at the discretion of the responsible license officer. Please contact us<julia.kuznets...@jetbrains.com?subject=IDEA%20license%20for%20OS%20development> to check the available options. *Apache developers*: Since *ASF* developers are often involved in several projects concurrently, JetBrains will provide them with personal licenses for individual developers, rather than on a per-project basis as we normally do for other Open Source projects." http://www.jetbrains.com/idea/buy/buy.jsp#openSource
