So, DOMMatrix (and the other geometry classes) are intended to be generic. So, then DOM seems out of place when, for example, using DOMMatrix in a WebGL application because there is no DOM inside a WebGL context.
I think better names would be TransformationMatrix, AffineMatrix, Matrix3D, or similar.
Calling it a DOMMatrix is like calling it a WebGLMatrix then using that to manipulate CSS transforms, which isn’t WebGL.
It might be a technicality similar to DOMString; implementation details specify it must be UTF-16, so runtimes that don’t internally represent strings that way must convert their strings to a DOMString first before interacting with DOM interfaces.
@Tigt But I feel that DOMMatrix simply isn’t generic enough. It makes sense if you’re working with DOM, but not if it is being used inside Canvas 2D or WebGL contexts.