The Sustainable Software Initiative

The Sustainable Software Initiative (SSI) is a non-profit organisation dedicated to defining and promoting collaborative source software (was previously "The Collaborative Source Initiative". Any terms referring to "Collaborative Source" should be now converted into "Sustainable Software").

The basic idea behind sustainable software is very simple: To combine the best of open source and proprietary world in one simple license definition. Otherwise speaking, to provide a sustainable commercial business model for a software company based on license revenue streams while keeping most of the advantages of open source software and community based development.

This mainly consists of:

1. Providing free access to the source code for anyone, anywhere, at any time 
2. Allowing any party to freely adapt, enhance, extend or distribute the code
3. Allowing license royalties based upon certain types of execution of the program or its derivatives (e.g. internal deployment use or commercial use) 
4. Allowing developers to be fairly rewarded for their work (for example accepting discounts on the license fee or granting to them stock-options or shares proportionally to the value of their contributions = Contribute or Pay Paradigm)

In opposite to Open Source licenses, a sustainable license enforces a strong quid pro quo philospophy. We think that it is the best way to ensure the availability of high-quality, rapidly evolving software while keeping full and free access to the whole source code. Active contributors within the community will receive some fair compensations pro-rata their commitments to the project. Technology free-riders will be taxed and will need to pay a cash royalty that will finance the work of other community members. So, in summary this licensing policy is harmful only to the one who attempts to get an unfair benefit of other peoples' work. This choice is completely up to the user. 

Please read the Sustainable Software Definition and Sustainable Software Paradigm to better understand the key criteria behind such licenses.

Even if the sustainable software idea is quite easy to understand at a first glance, it involves many new ideas, solves a lot of existing business issues in the open source world and allows the creation of new viable commercial business models.

You can read success stories and best practices about software products that are already using a sustainable license here.

This site is still evolving as we are still learning all the implications of sustainable software in the commercial world. We don't claim to have all the answers yet, so mail us with your ideas and criticisms. Also, do not hesitate to send us URLs of articles and papers about the similar business model, on other new sustainable software, or on any other related topics.

You can find copies of approved sustainable licenses here. Please send us an email if you want to add your own compliant sustainable license.