Can Unity be used to create a scene editor?

Unity Engine
1

My company needs to develop a scene editor.

However the Unity license states “Unity cannot be used to write a competitor to Unity”.
Does this mean I cannot use Unity to make a 3d scene editor tool (with a standard 9-axis 3d gizmo UI control)?

We have our own OpenGL based movie player, but our customers (graphic artists) need to project movies on architectural pieces (projection mapping).

Most of our customers use Unity already, so it would be nice if we could give them a stripped down
version of Unity to allow them to visualize and EDIT the video projection map they create.
By stripped down version, I mean a version of Unity that only renders wire frame 3d models, and simple RGBA colors, but no textures.
We cannot afford a $3000 Unity license for each of our 1000+ customers.
However, we could afford a more reasonable licensing scheme (maybe for everyone on our team?)

I could not find this control in the Unity store, so I suspect the reason is because you are not allowed to write this control.

The only other option I can find so far is MIT-licensed OGRE+Ogitor.
Anyone have other suggestions?

2

You can make this kind of thing provided it’s not too close to unity. You cant e.g. just wrap lots of unity functionality in some slightly different user interface, like having c# and unity scripts, or reproducing a lot of what is standard in unity. At least thats my take on it. A long time ago I was going to create a game editor and I emailed to ask them about it. They said it would probably be ok - unity is intended to facilitate creation of multimedia products, games, apps, etc… editors too… you just have to have enough that is unique and different and not just some obvious ripoff… if you were to use it to like, let people create unity-like games for example, probably pushing it too far. If I recall they also said that when I got closer to a final product I could send it to them and they would assess it (with their legal team?) and let me know if it was acceptable… doesn’t hurt to ask them.