Distribution of application with Apache modules

Question

I am about to release my first ever app, I have used a library that is licensed under Apache 2.0, my question is do I need to communicate with the library owner before I release it or in case I decide to monetize my app am I by any means obligated to sharing my revenue with the library developer? lastly do I need to make my entire app open source as well or its only changes to the library that I need to publish? thank you in advance.

Answer 1

The apache license grants you in its article 2 the right of creating your own app based on the licensed code, and if you're selling it, even without financial compensation of the original authors:

(...) each Contributor hereby grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare Derivative Works of, publicly display, publicly perform, sublicense, and distribute the Work and such Derivative Works in Source or Object form.

There are some conditions however when you distribute your app (and hence redistribute the licensed apache code) in article 4. Read them carefully, but they are mostly on communication of the license terms and modified items.

So you are not obliged to seek approval of the library author (e.g."contributors"). You can nevertheless inform him. He will be pleased. Some authors even maintain a list of software using their library which could give you some additional audience.

You have no financial duty at all, whether you give your app away for free or commercially. But many open source projects are poorly funded and could welcome a donation to help them finance their project (e.g. hosting costs, etc...). So if you earn some money thanks to this library, you should consider at least a symbolic donation.

Aditional resources:

• Comparison of open source licenses
• Wikipedia comparison of licenses
• Apache license for the non lawyers

Disclaimer: this is not legal advice. This is only my personal opinion as an IT professional. For legal advice you should contact a lawyer or a qualified legal expert authorized to give legal advice in your jurisdiction.