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MySQL database licensing

I have a question about the appliance of the current license Epic Games uses in regard to third party products. To sum it up, basically it's illegal to use third party products like MySQL unless you pay for a license (which could cost a handsome couple thousands of dollars). Is it also illegal to use a workaround for this? For example, am I allowed to make cURL calls to a webserver, which in turn is connected to a MySQL database? Or am I allowed to use alternative solutions to MySQL like MariaDB, PostgreSQL, or SQLite? If not, it would be a bit rough on start-ups to get a system like that going unless they have a solid invester willing to pay for licensing costs.

Product Version: UE Github Master branch
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asked Apr 02 '17 at 03:10 AM in Legal & Licensing

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avatar image atypic STAFF Apr 02 '17 at 10:56 PM

I don't think I understand the question. To the extent that you're asking about third party software licensing terms, I'll lave it to someone else to answer.

avatar image bcnobel Apr 04 '17 at 02:27 PM

According to Shadowriver's answer on this page: "MySQL library free licence is GPL. which UE4 EULA prohibits to use with UE4 because GPL force software that use GPL library to also be GPL licenced which would make UE4 free redistributable without any money benefits to Epic".

PostgreSQL is released under the PostgreSQL License, a liberal Open Source license, similar to the BSD or MIT licenses. Does this mean that I am allowed to use a PostgreSQL server for my project? The same question pretty much goes for cindustries' unreal-sqlite3 project, which is licensed under MIT.

According to this website, the MIT license allows commercial use. Can I safely assume that anything licenced under MIT is compatible with UE4's EULA?

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2 answers: sort voted first

Using PostrgreSQL/unreal-sqlite3 is the safer and more conservative approach, and both are fine to use with UE.

MySQL, without the commercial license, may be OK, depending on the nature of the use, but its a fact-specific question without a clear answer.

In response to your final question, the MIT license is OK for use with UE, as are the BSD License, Microsoft Public License, and the Apache License. These licenses are expressly called out as permitted under Section 1(b)(ii) of the EULA.

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answered Apr 04 '17 at 03:51 PM

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DudleyStephens ♦♦ STAFF
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These answers are incorrect regarding the use of MySQL in the manner that you have described in your question.

I'm not a lawyer so do not take this answer as solid legal advice, but generally speaking:

Keep in mind that there are separate licenses for both the MySQL database engine itself and for the various connectors used to communicate with it directly.

My understanding of the usage you describe in your question is that you mean the client would be calling to a web server that you do not distribute to clients as part of your game. If you are using MySQL in that manner, you would not be redistributing MySQL or its connectors to users so licensing is not a concern for you in that aspect. The GPL license only affects code that you distribute to other parties. Internal usage within an organization is totally free and not subject to any conditions. There is no such thing as 'internal distribution' that would restrict the usage of your code by requiring it to be GPLed.

Connecting to a remote service that runs MySQL (or MariaDB or any other GPL software) in the background is also free.

For internal programs for which you own all the copyright(s), there is essentially no risk in using GPL software. The argument you can use in your defense is that if the software became GPL as part of the distribution, you as the copyright holder could immediately revert your part back to its original copyright. No one has the right to require you to reveal or redistribute your code to the outside of your organization even if you would have distributed it internally linked with GPL software!

The above is an excerpt from MariaDB's creator (who is also the creator of MySQL) and he is the one who chose GPL licensing for MySQL) so while he may not be a lawyer either, I would assume he knows a thing or two about the licensing and its implications ;)

For full reference please see the following page this information was drawn from by visiting this link

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answered Jan 03 '18 at 07:01 PM

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avatar image DudleyStephens ♦♦ STAFF Jan 05 '18 at 01:43 AM

I'm Epic's attorney, so I can't provide you legal advice about the interpretation of the GPL. That being said, I've shared below Epic's position on the matter.

It is correct that the "viral" portions of the GPL are triggered by distribution and not by mere use of GPL code in combination with non-GPL code. However, what constitutes a distribution under the GPL is not clear. While it may be the case that the author of a particular program licensed under the GPL construes distributions narrowly, Epic takes a conservative approach and treats distribution broadly. For example, Epic would consider placing software on a third-party web server a distribution. That means that it would not be permitted under the UE4 EULA to use GPL licensed code with UE4 and run the resulting code on a third-party web server.

There are possible ways to use GPL licensed code with non-GPL licensed code without making the latter licensed under the GPL. For example, one could have a non-GPL licensed client interact with a GPL licensed server. However, as mentioned, these situations are fact specific. Using PostrgreSQL/unreal-sqlite3 is the safer and more conservative approach, and both are fine to use with UE4.

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