There are plenty of tools for making images. I'm not looking for one of those; I have many tools for creating an image. I've got tools for compressing images, generating mipmaps, and even for poking at their basic data format.
My issue is with texture assembly. DDS files support cubemaps, array textures, and even cubemap arrays. But I don't know of a tool that can pack a series of images into a cubemap or the like. What tools are available for doing this kind of thing?