I am developing a piece of software.
I really want to open it up to the open source community…but I also want to retain some ability to profit from the sale of the software.
Are these desires totally incompatible?
Is it possible to release it under terms something like this:
This software is free.
You are free to alter and modify the source code as long as you include this copyright statement.
You are free to modify, repackage, and sell this software (just like Redhat Linux) with the following condition: You must give 1% of the gross revenue from software sales to the original copyright holder.
Is such a thing an option?
Could Linus Torvalds have done that and if so, wouldn’t he be enjoying some nice royalties from Redhat right now?
You certainly can do that. You can make your license say anything you want. Almost all open-source licenses are additions to copyright, by which I mean that that copyright still applies but the license gives the user additional rights they wouldn’t normally have under copyright as long as they abide by conditions, and you could make those conditions whatever you choose.
From a realistic standpoint, many open-source advocates would call your license “non-free” and it wouldn’t really be accepted by the community. Many open-source advocates don’t have a problem with charging for software as long as the source is free and redistributable, but I think most would balk at your license fee. That doesn’t mean it’s an unreasonable license, just not in line with open source convention. It also means you have almost zero chance of getting included in most software bundles (e.g. becoming a default install option in a Linux distro).
To make a decision on what you can realistically earn from open-source software, you need to look at your audience. If your app is aimed at high-end techie users, then it’s quite likely you’d never earn a dime trying to sell open source software because these users will simply compile from source. On the other hand, if your app is aimed at a broader market of less technical users, most of them will purchase your software rather than compile it. This is especially true if your software is aimed at Windows users rather than Linux. If you are aimed at this broader market, you might consider just applying a standard license like GPL to appeal to the open-source community and making the binaries convenient enough that people are willing to pay for them, but if your paid product doesn’t add value, you run the risk that some other techie will just make free binaries available elsewhere. It’s especially likely if you apply your license fee condition that someone will just distribute your app for free to subvert your conditions.