Thursday, February 19, 2009


Open Source ChessFlash

As I just posted at I intend to make the source code available for the ChessFlash Viewer available under an open source license. I need to research some different open source licenses and consider a few other issues but I plan to do this fairly soon.

Part of my motivation is a relative lack of time for customization and new features. I wrote ChessFlash while not otherwise employed last year but I have started back working at a "real job." I've had some customization requests that would make the ChessFlash Viewer better and more widely used.

Does anyone have thoughts / advice / words of wisdom on the matter?


This is great!
Depends on what your final goal is with chessflash.

Without enough knowledge of open source code legalities and such, giving out the code seems like a trap door. Even if you decide to pull back the code later. So just make this is what you really want to do.

Of course, I wouldn't mind seeing the source out of curiosity. :D
liquideggproduct:I have been approached by a couple of organizations about modifications to ChessFlash to allow them to use it on their site (and store the games on their site, load the tool from their site, perhaps add some other customizations, perhaps not). Among other things, changes that remove any dependencies on me personally or on my ChessFlash web site make the tool a more viable strategic choice for certain organizations (they don't want to committ to using a tool that would fail if my web site went down).

Both have talked in terms of paying me to make changes or to sell the source. I want to avoid direct payment since that implies a commitment to support and I don't have the time. I would like to see them and others use the tool so I would rather make the changes for free or make the source available for them to modify than charge to make the changes.

Also, now that I am back at work, I want to scrupulously avoid any real or perceived conflict of interest with my employer (a commercial software company) and a free open source "hobby" is more consistent with that than running a commercial software business on the side. Open source and free software philosophies have some bearing on my thoughts as well.

If I release the code as I intend under an open source license then I can not revoke that later. OTOH, as the copyright holder I can still do "other things" with the original code if I so choose (later offer a commercial version, for example) -- but I don't really expect to. Of course, those "other things" then need to compete with what others may have done based on the open source version. But most open source software suffers from development neglect and lack of attention and I have no reason to expect anything different for ChessFlash.

As you and I have discussed, there are some things that I would like to do "some day" with ChessFlash including a full featured user friendly chess authoring tool. That tool might be integral to ChessFlash or independent of it. Either way, I don't see this step as preventing those next steps...
Hi Glenn, I see you have chosen the GPL which is a fine license, so my comments probably come too late. I just want to respond to some of your comments above.

You said "If I release the code as I intend under an open source license then I can not revoke that later."
That's not true. If you are the copyright holder, you can change the license at any time, even with the GPL. It happens all the time.

Personally I tend to prefer BSD style licenses. The are just easier to work with. Say you would like to use part of your own GPL'ed code with your (supposedly) closed-source employer: well, you can't, without making the company product also GPL. The GPL is said to be "viral" in this sense. It's a good intentioned virus, but nonetheless forces you to do certain things. It depends on your employer, but in my experience the answer is typically "let's not use that code".

BSD licenses allow you to simply take the code and use it, no question asked (more or less).

Thanks for your thoughtful comments.

My understanding is that once I released ChessFlash under the GPL it (that version or versions) is always under the GPL. I can't unrelease it or withdraw the license after the fact. But, perhaps I am mistaken -- it is not an important point for me.

As the copyright holder I can always release it under different additional licenses and I may if someone has a need for other licensing arrangements. Of course, if I have accepted source code contributions from others then that may complicate what I can do with the code.
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