In November a Mark Schonewille posted a blog on when you can't and cannot use the GPL version of MySQL together with your closed source application. The post was a result of actually talking to an Oracle lawyer which makes it valuable information. Unfortunately Mark's blog is now offline (it seems he didn't renew his domain registration?)
This is just a repost of the disappeared blog post. (The small print allows me to copy it verbatim.) There is no commentary from myself, except that what Mark wrote is the same I also heard Oracle say a year ago. That Oracle is being consistent on this point is very welcome and deserves to be kept available online.
Update 2011-06-23: Mark comments that his blog is still online, but at a new address: https://qery.us/tl
MySQL LicensesThe Do's and Don'ts of Open Source, or What's All the Fuss About?copyright ©2010 byMark Schonewille and Economy-x-TalkNijmegen, the Netherlandsthis version: 1.3 (26 Nov. 2010)1 IntroductionIn reply to a question on the LiveCode User Mailing List, I argue that MySQL is one of the best freely available (open-source) databases. A number of subscribers to that mailing list reacted quite strongly, saying that open-source doesn't mean free. Apparently, they use the
word "free" as in "free beer", while I use it as in "free speech". They argue that one needs to pay Oracle Corporation a lot of money if one uses MySQL, despite the fact that MySQL is open-source and freely available.This was enough reason for me to call Oracle Corporation. After 30 minutes of searching for the right person, I was connected to a friendly Oracle Corporation employee. I asked this employee three questions: 1) do I have to pay Oracle Corporation if I use MySQL at home, 2) do I have to pay Oracle Corporation if I make commercial software that works with MySQl and 3) do my customers have to pay Oracle Corporation if they use MySQL in combination with my commercial software? His answer was a resounding and clear threefold "No!"One doesn't need to pay Oracle Corporation. It should be clear, though, that MySQL's license, specifically the GNU General Public License (GPL for short) requires it to stay open-source. The GPL poses a few limitations on the use and distribution of MySQL, but creates opportunities at the same time.In the text below, I explain the implications of the GPL for users of MySQL. In doing so, I will discuss a number of typical examples.2 Unpaid Without RedistributionYou can freely download the MySQL software from the website. You can install it on your laptop for your own personal use, to test your website with a MySQL server. You can upload those websites to a web hosting server. You don't need to pay Oracle Corporation anything in this situation.A web hosting company can offer the MySQL database engine as an extra service on their servers. They can freely download the MySQL database engine from the MySQL website and they don't need to pay for it. The customers of the web hosting company also don't need to pay for using MySQL with their websites.As another example, a printing company wants to manage a large customer database and has MySQL installed on an internal (local) server after downloading it from the MySQL website. The printing company is allowed to use the MySQL database for free without paying Oracle. The same company can ask me to make software for them, which will talk to their MySQL database. That company still doesn't need to pay Oracle Corporation and I myself don't need to pay either.In a third example, I make commercial software, which needs to have MySQL installed. My customers can use my commercial software, for which they do need to buy a license, in combination with the MySQL database engine, for which they don't need to pay. Because the MySQL engine is not embedded in my commercial software and I don't redistribute MySQL together with my software, I don't need a commercial license for MySQL and neither do my customers.The next situation is a little tricky. I make commercial software and need a special version of MySQL to make it work. I adjust the MySQL engine and distribute it as open source
software. I offer the source code for free to everyone who uses my adjusted MySQL database engine. I simultaneously distribute my commercial software accompanied by a note that it needs the adjusted
version of MySQL. I make sure that the original GPL applies to my customised version of MySQL. I tell my customers to install my version of MySQL on their servers and to install my software on their client machines. I don't need to pay Oracle Corporation because I distribute the adjusted version of MySQL under the GPL and it is not embedded in my commercial product.This is about as far as you can stretch the GPL. In the situations described in the above, I don't act as an OEM (Original Equipment Manufacturer), an ISV (Independent Software Vendor) or a VAR (Value Added Reseller) and I, my customers and my (internet) service provider can use MySQL without paying Oracle. (Note that redistributors are not limited to OEM's, VAR's and ISV's only).3 Redistributing the MySQL SoftwareThe next step would be to adjust the MySQL engine in such a way that it can work with my commercial software product without distributing the code for the adjusted engine. This causes a dependency between the MySQL software and my commercial product and violates the GPL directly. The GPL can no longer apply and I will need to buy a commercial license from Oracle Corporation in this case.I could download the MySQL engine and embed it into my product, e.g., by letting my installer install MySQL automatically together with my own product. I don't want
to disclose the source code of my entire product. Because I am selling my commercial software product together with the embedded MySQL engine, I have become an ISV and I need to buy a special commercial license to do so.It should be obvious that I also need to buy a commercial license, if I want to use the MySQL source code libraries, rather than compiled binaries, in the source code of a commercial product without revealing the source code. Selling this commercial product violates the GPL and requires that I pay Oracle for a license.However... as long as I have no desire to sell the embedded MySQL source code commercially, I can let the GPL license apply. For example, if the aforementioned printing firm asks me to create an in-house tool to manage their database, they might require that the tool includes the MySQL server (either by embedding the source code into mine or by combining the binary with the final product). If I make the tool, include MySQL in it and license it to the customer under the GPL, my customer has no obligation to reveal the source code to anyone, as long as he doesn't redistribute my work. The customer still doesn't need to pay Oracle Corporation for a MySQL license, nor do I.However (again)... I have to offer my customer the source code as required by the GPL. If the customer doesn't want the source code, I don't need to give it to him. If the customer wants to redistribute the product, he needs to ask me for the source code, because he has to make the same offer to those who receive the redistributed software from my customer as I had to.The interesting point here is that my customer still can (or rather has to) pay me for my services. I made the software for him and he already agreed to pay me for my efforts. When he
redistributes the software under the GPL, he can offer his own customers a similar service.4 Then What's All the Fuss About?It is quite obvious that Oracle Corporation doesn't write on the MySQL website "please don't pay us". However, the goal of MySQL isn't only to generate money. By supporting MySQL, Oracle Corporation makes sure that a large community of software and database developers continues to exist. This community creates new ideas that Oracle Corporation might use —reverse engineer, if you want— in their commercial products. Another reason to support MySQL is that some customers might prefer the commercial Oracle database over the non-commercial MySQL database at some point.If you decide to pay for a MySQL license, you don't actually pay for the software. The software is open-source after all and can't be sold without offering the source code. If Oracle
Corporation would ask loads of money for the software only, someone would decide to compile the binaries and offer them for free, together with the source code. Anyone could do so.Also, Oracle Corporation can do exactly the same as you and me: sell a service connected to MySQL. Oracle Corporation provides support to anyone who wants to pay for it. This way, MySQL is a source of revenue for Oracle Corporation.Finally, there are the licenses for OEM's, VAR's and ISV's. Everyone who wants to sell MySQL software as part of their proprietary software or hardware product needs to buy a commercial license. This is another source of revenue for Oracle Corporation.For most small businesses, MySQL is the least expensive (or even completely free) and often the most efficient database available, provided that they don't need support from Oracle
Corporation. For example, being a small company with all necessary skills available in-house and not having huge databases that require continuous monitoring, Economy-x-Talk doesn't need to buy support from Oracle Corporation.5 Conclusion: Redistribution Is KeyThe conclusion of this story is twofold. First of all, as long as you don't redistribute the MySQL software, you don't need to worry about licenses, even if you make money by providing database-related services or products that need MySQL to be available. Second, even if you redistribute MySQL under the GPL, you can still make money with it, as long as you offer the source code of your project, which your customer might not even want to have.To clarify the second conclusion, keep in mind that it is not obligatory to redistribute your compiled software. When you offer the source code, your customers are not obliged to accept the offer. Because you are the one who provides the service of maintaining and improving the software and your customers are actually already paying you for this service, they might not care about the source code. Only if you ever decide to stop providing this service, your customer
might have an interest in the source code.Oracle Corporation seems to stick not closely, but completely, even literally, to the GPL. All the fuss about Oracle Corporation no longer supporting MySQL and not caring about small
companies who use the MySQL database engine is sheer nonsense. Oracle Corporation continues to support MySQL for now. Even if they decided to terminate their support, anyone could take the MySQL engine and continue to develop and redistribute it under the GPL.Note:Please, feel free to comment on this article. Keep in mind, however, that I asked Oracle Corporation for their opinion on this matter and, although not in as many words and not that specific, this was their answer. I would like
to thank Björnke von Gierke and Judy Perry for their comments.The author owns the software development company Economy-x-Talk and gladly offers his services. Need help with LiveCode, PHP or MySQL? Let me know !The author accepts no responsibility for any consequences of business decisions based on this information. It is the reader's responsibility to read the actual license conditions on Oracle Corporation's MySQL website and consult with Oracle Corporation if in doubt. This article represents the personal opinion of the author, is not endorsed by RunRev Ltd. and has not been authorised by Oracle Corporation.Integral reprint in physical and electronic form is herewith granted, on the condition that the copyright notice, the version number, the date, the URL's and this sentence are included. If you publish this text on a web site, please embed the URL's in a sensiblel way.