A commercial software but open and free for personal/edu. How to license?

Question

I am developing a software to sell for business use but am willing to make it free and open-source for personal and educational use.

Actually I can see the flowing requirements I would like the license to set:

Personal and educational usage of the program and its source codes is to be free.

In case of publishing of derivative works the original work and author (me) must be mentioned (incl. textual link to my website in a not-very-far-hidden place) and the derivative work must have different name.

A derivative work can be closed-source.

In every case of commercial (when the end-user is a commercial body (as a company (expect of non-profit organizations), an individual entrepreneur or government office)) usage of my work or any of derivative works made by anyone, the end-user, service provider or the derivative author must buy a commercial license from me.

I mean no guarantees or responsibilities, whether expressed or implied... (except the case when one explicitly purchases a support service contract from me and the particular contract specifies a responsibility).

Is there a known common license for this case?

As far as I can see now it can not be OSI-approved as it does not comply to the §6. of OSI definition of open source. But there still can be an a common known reusable license for this case as it looks quite natural, I think. In case there isn't, I am going to write my own. Would you please share your thoughts on what paragraphs is such a license to specically contain?

Answer 1

Well you are trying to design a proprietary license here. Because of the No Discrimination Against Fields of Endeavor clauses your app will never be included in any of the linux distributions.

You are better off taking an open-source licenses and add your additional clauses to it.

1. Rename clause can be borrowed from TeX license (but it is stupid imho)
2. Attribution is common in many licenses, including BSD (this whole copyright present must be presented in accompanying documentations etc) NB do not use advertising clause though.
3. What do you mean by derivative works can be claused-source? What's the difference between personal, educational and commercial usage? Can you please define that? Is tutoring students for money and using your software education or commercial usage?
4. The warranty clause can be taken from BSD license again.

It is hard to answer your question because you made up the clauses already before hand (in a free-form text not legal) without explaining why you want such terms.

I suggest you to take two licenses - one open-source and the other one proprietary:

1. If your field of endeavour is personal or educational, you can use my software under GPL license.
2. If your filed is also, changed to or is commercial, you can buy this license.

See Tetgen license for a similarish license in-spirit http://tetgen.berlios.de/

Answer 2

I am not familiar with an existing license that fills all your requirements: However, the underlying tone of your request is along the lines of a dual-licensing scheme, which can be fairly commonly found in the open-source community (similar to what Dima has suggested).

Basically this is where you make your software available under two different licenses, one typically open-source and another with a closer resemblance to a propriety license. However, I am not familiar with any dual-licensed projects forcing your requirement of

every case of comercial (use) ... must buy a commercial license from me’

In these sorts of arrangements users are typically free to pick and choose the license they desire, as the open-source licenses don’t restrict usage based on consumer type (they are open to all).

The questions I think you need to ask yourself:

• Do I really need to give personal and educational users of your software the source-code to the product? (If no, educational / personal licensing schemes are commonplace in the propriety world –MS Word for example).
• How ‘open’ do you plan on making the source code to your personal and educational users? Dual-licensed projects using OSI licences mean that derivative works can be completely free – i.e. with none of your commercial restrictions.
• Why do I want personal and educational users to have the source-code? If one of those reasons is, “to help improve the product” – how are you going to encourage personal/educational users to make contributions to a product that you are forcing to be sold to a particular consumer type? Most dual-licensed projects are geared around providing a service rather than a product under the commercial ‘half’ of the license, i.e. support, training, etc.

Having a read of the producing oss book – in particular the sections on “Free” versus “Open Source” as well as the “dual licensing” sections. I think will help clarify if you want to open the source code to your project at all.

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However, when in doubt - it is always best to pay a visit to a professional intellectual property lawyer for these kinds of problems.

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