What license for my program: Open source, freeware or shareware?

Question

I have been working on a tool for windows that I want to make public. However, I have a quandary. Do I make this tool open-source, freeware (source is not open) or shareware (free for personal use, pay otherwise). Eventually, I hope to make a Pro version that includes more features and plan to make it payware. I believe this in itself might preclude it from an open-source license since the derived Pro version will have to preserve the original license, right? What particular freeware/shareware license should I consider? Have any of you done this? Can you share your experience?

Thanks.

Answer 1

Not every open-source license will prevent you from developing a proprietary version. BSD and MIT/X11 won't for instance.

Answer 2

As long as you wrote all the code, releasing the code with an open source license (GPL/BSD/etc) doesn't affect you at all, only other people using your code. So the Pro version can still be released with whatever license you want.

That said, if the open source version may compete with your Pro version as the community adds features to it.

The safest choice is probably a freeware license, and if the pro version never takes off, you can open source it later.

Answer 3

There's no best answer here. One of my ideas started as closed source and later GPL'd following up on a promise I made to some users should I ever stop working on it (no longer online). My work on porting ANTLR for C# 3 is released on a BSD license, but my IDE for it is closed source. Another tool for Visual Studio was GPL from the start.

Answer 4

You still own the software, so can do whatever you want, including releasing a pro version with an entirely different license. The license you use will affect what other people can do with the open-source version.

Answer 5

You are not bound by the license you offer your users -- you could distribute it as GPL today, making it impossible for someone to take it, make improvements and then sell it as a paid product, but you would still be free to distribute it under a commercial license as well in the future.

This is the model that MySQL uses, although they started out commercial and add a dual license GPL option later.

The problem is that even though it may be open source, you are not able to incorporate outside contributions into your commercial version.

Answer 6

Open source or closed source is an orthogonal question from freeware, shareware, or payware.

You can release payware and open the source to people who pay for the product, and allow them to modify it. Or you can release freeware but keep the source closed to yourself.