Is it legally enforcable to demand that a specific version of third party software be used?
<p>I'm currently upgrading to the latest version of a commercial product (Let's call it 'Foo'). In their installation guide, they specifically say that the enterprise-licensed version of a third party piece of software (Let's call this 'Bar') must be used to run this product, rather than using the open-source community licensed version of this third-party product.</p>

<p>There is no technical limitation of the community version of 'Bar', indeed it is the same codebase as the enterprise edition. There is a significant cost to using the enterprise version of 'Bar' vs the community version.</p>

<p>I'm specifically interested in whether they can legally enforce this in order to license their product, not what they might/might not do or support.</p>

<p>If I enter a commercial contract, then this contracts becomes the law between the parties within reason. So if I agree to the contract and the contract says that I cannot use the foo open source package in conjunction with this commercially-licensed component, I guess I can either comply or not comply and this becomes a commercial contract issue, and any violation becomes a commercial and contractual matter: this has nothing to do with the fact there is or not an open source version of the widget. It could be a commercial widget too.</p>

<p>An open source version of a dual licensed package may not have any restriction on usage, but here a commercial contract can do this alright IMHO.</p>

<p>Now, to take a practical example, say I have a license to use SuperWidget which works with MySQL; let's pretend that the commercial contract I signed for this license with SuperWidget Company says:</p>

<p><em>"You must purchase a commercial license for MySQL from Oracle when using MySQL as the SuperWidget database. You cannot use the community, GPL-licensed version of MySQL with SuperWidget; this will void your warranty. SuperWidget really needs certain MySQL enterprise features not present in the community edition or else all hell will break lose and SuperWidget will crash badly."</em></p>

<p>...then I would think I would need to buy this, whether I like it or not; OR I should not enter in a commercial contract in the first place with SuperWidget Company or negotiate with them different terms.</p>

<p>All that said, I would take this with a grain of salt as it could very well be contract provisions that could be unenforceable or plain illegal in some countries or states.  And it could be considered an anti-competitive behaviour in some places too..</p>

<p>I am not a lawyer so I would strongly advise you to consult a lawyer as the terms of such a commercial contract would need legal review for sure.</p>

<blockquote>
  <p>I'm specifically interested in whether they can legally enforce this in order to license their product</p>
</blockquote>

<p>Yes, they can legally enforce this.</p>

<p>Software 'licences' have two kinds of teeth: as licences (for copyright mostly, but also patents etc), and as contracts. </p>

<p>Violating a condition of your copyright licence means you no longer have permission to use the copyright in the software, which means that your use of the software (which inevitably involves making copies of the software) is a violation of copyright, which results in you having to pay damages (money) to the copyright owner. Copyright damages may be 'statutory damages', which works a lot like a fine, or actual damages, which is based on the injury or cost inflicted on the copyright owner by your violation.</p>

<p>Violating a contract (i.e. failing to do what you promised to do under the bargain) results in you having to pay damages (money) to the other party to the contract. There are no 'statutory damages' for breach of contract; you just compensate the other party for whatever injury (cost) they have suffered.</p>

<p>The next question is whether the contract is void under some special rule.</p>

<p>Generally speaking, you can contract for whatever silly or frivolous promises you like (e.g. 'I promise to only wear X brand of shoes while in public'). This is called 'freedom of contract' and is given great weight by common law courts.</p>

<p>A contract can be avoided if it is an unreasonable restraint of trade. The exemplar of this category is an agreement by a baker to never bake another loaf of bread again. A court will not enforce that. However, there are limits on the principle. For example, a court will enforce a promise by a baker to not open a competing bakery within ten kilometres in the next two years; such a promise is reasonable (in the common law's book) as, for example, part of an agreement for the sale of a bakery business.</p>

<p>At most, the contract in question could be said to restrain your freedom to use whatever software you like. This is unlikely to be enough to get the contract avoided. Even if you got 'prima facie' into a special rule, the copyright owner could probably persuade the court that you fall outside of it because the contract served a legitimate purpose such as (a) protecting them from support demands or reputational risk if you use unsupported third-party software and complain when one breaks the other and/or (b) providing what is essentially a 'package deal' for the sale of the two pieces of software together.</p>

licensing