How to open "BigTIFF" files? I'm looking for some software that would open BigTIFF files on a mac - ones that are 6GB or bigger. (I'm not opposed to writing some code to do so, but I'd prefer a prewritten solution.)

Does macOS have any built-in software to handle this sort of thing? If not, are there any commonly-used external programs or libraries that I could employ?

I just need to view the images and be able to zoom in - I don't need to edit them.

NOTE:

Just to be clear, I am not wanting to view large TIFF images. I am specifically referring to bigTIFF images. If you are not familiar with these, please refer to http://bigtiff.org/
Yes, macOS includes the Preview app which can open large TIFF images.

By default, the Preview app is located within your Applications folder.

The Preview app actually offers a lot of functionality, including:


opening images and PDFs
editing images and PDFs
signing documents
sharing files
annotation


For more details, see this page.

If I've misunderstood your question, please feel free to clarify it.