I made some modifications to the Unity Pro Water4 system (I added flowmap support) and would like to share my result with my peers in a blog post or something. I was wondering what the legal restrictions are on what I can share.
Can I only share my additions to the shader/script code? Can I also share the code I removed or altered? Or can I share everything since the underlying requirements (render textures) are only available in Unity Pro?
I believe the Unity license allows you to use any of the Unity-created assets in a Unity project, royalty-free. (This is why some douchebags are able to put Angry Bots unmodified on the app store for .99 and not get taken down) This is done so that Unity users don’t have to worry about whether or not they’re using too much of Unity’s content.
I’m not 100% sure that this policy extends to blog posts, though. Using Angry Bots assets in a publicly released game that was made on UE4 would almost definitely not be okay, for example. A Unity-centric blog is a bit of a gray area there.
Is there a particular channel of communication I could use to find out from Unity what is acceptable?
Someone from UT will most likely swing by this thread sooner or later.
And if they don’t, then you could always try complaining that UE4 would allow you to share the assets. That always draws out the UT employees 
Woo, that sound like a good assets.
For your concern, anything come from Unity Technology is safe to be reproduce, modified and redistributed.
Do you have some reference I could use to prove that? I would like to trust you, but you can’t trust everything you see on the internet. 
It’s okay, you can trust me. I’m George Washington. Would George Washington lie to you?
Still waiting patiently for a response to this, either directly or with some pointer to an official response on a similar question…
I think you are fine sharing your mods. All the Unity provided stuff is free to use with Unity and since none of it will work with Unity free, you should be fine. If you want to be really sure, you should contact them using their contact page:
Let me tag some people who are knowledgeable on this subject and might answer your question.
We generally view our distributed content as ‘public domain’, so any of the Learn assets, Standard assets or Sample Assets, you can feel free to do whatever you want with! To the best of my recollection, there is some legalese in the EULA which mostly points out that you shouldn’t be trying to sell anything on or use it in projects outside of Unity but that’s about as restrictive as it usually gets.
Thank you!
I did see it from Unity website itself, but it’s been a long time.
And it seems you’ve been enlightened as well. 
Would love to see that blog post once it’s up! =)