Log aggregation and analytics is a hot space at the moment and in all fairness I think that you are being taken advantage of. I've read the messages and you are under no obligation to provide free support for source code and you shouldn't be bullied into doing so. In my eyes you have gone far enough in providing the source and binaries.
I think your biggest problem isn't your licensing but the documentation and the site itself. Since I work in the same space for a commercial product similar to Splunk, I'd like to offer a few comments.
1. It needs to be clear what the difference is between the enterprise and the open source version. Features and support must be clear with the enterprise version.
2. The message has to be clear for the target audience. Your product is very developer focused, but you have many support use cases. Focus on making it easy for non technical (non dev) people to get started monitoring the most popular pieces of infrastructure. A few getting started or how to guides for popular web servers and databases is a good start.
3. You may also need to cripple the functionality of your product (for the free version). Perhaps cripple it based on scale. The number of agents that can be deployed in an env can be restricted. Don't do what splunk do a disable based on data volume.
4. There are no images on your site. I can't visualize how I would instrument my infrastructure for log collection. This is vital.
I haven't used nxlog but this was my first impression. I hope the comments help in some way.
However, if you do choose to release your software under GPL or LGPL you also
place yourself under an obligation to provide build instructions. This is not
what I say, it is what the GPL/LGPL themselves say.
This is wrong. Section 4 of the compliance guide, from which Mr. Main proceeds to quote, is directed towards those distributing GPL software written by other people. The GPL does not place any such constraints on the author(s). If you want to distribute Windows binaries, and don't want to bother explaining how to build nxlog on Windows, you are completely within your rights. If Mr. Main cannot figure out how to build it on Windows, he is simply unable to distribute a modified version that runs on Windows (since the GPL would require him to explain how he did so), and you are not obliged to lift a finger about that.
While reading the emails, I do want to correct one thing.
The author to a copyrighted work are not obligated by the choice of license. GPL and other copyright licenses give people other than the copyright holder a licence to do things that they don't have under regular copyright law. The copyright holder however has full rights regardless of license.
The only exception is false advertisement laws, but those are quite narrow in definition, and might not matter much for non-paying customers. A paying customer would have a case however.
My advice would be to setup a paid support arm ASAP, and tell the person complaining they have two options:
1) Log a bug against the windows build process, and you'll look at it when it reaches the top of your priority list, or
2) Engage you for paid support to investigate the issue.
You are under no obligation to make your softwear buildable on any platform. If he chooses to disagree,he can refuse your license, delete your software and move on.
Paid support is already there. There is a "support" menu on the webpage, the issue tracker has a polite note saying that this is available. Some people have been contacted directly in email to see whether they'd be interested.
For example some users at a big Taiwanese laptop maker company were after windows2000(!) support. When they were politely offered support saying "please decide whether paid support would be of interest or not", the response was "ok, thank you for your information but when can you fix the bug?".
I could give countless other similar examples.
Anyway, thanks for your suggestions. I'll heed the advice and will change the website to make this more clear for those who are only after the free labor.
I think your biggest problem isn't your licensing but the documentation and the site itself. Since I work in the same space for a commercial product similar to Splunk, I'd like to offer a few comments.
1. It needs to be clear what the difference is between the enterprise and the open source version. Features and support must be clear with the enterprise version.
2. The message has to be clear for the target audience. Your product is very developer focused, but you have many support use cases. Focus on making it easy for non technical (non dev) people to get started monitoring the most popular pieces of infrastructure. A few getting started or how to guides for popular web servers and databases is a good start.
3. You may also need to cripple the functionality of your product (for the free version). Perhaps cripple it based on scale. The number of agents that can be deployed in an env can be restricted. Don't do what splunk do a disable based on data volume.
4. There are no images on your site. I can't visualize how I would instrument my infrastructure for log collection. This is vital.
I haven't used nxlog but this was my first impression. I hope the comments help in some way.