The title of this post over at Tedium, ‘10 Image File Formats That Didn’t Make It’, isn’t strictly correct, as at least two of those file formats are still in use today. But the remainder form a nice little potted history of the development of computer graphics over the decades.
While I doubt I’ll ever encounter any of these in the near future, it’s reassuring to know that GraphicConverter will probably be able to open them. :)
One important takeaway from the Tedium post, which I was reminded about recently when opening some old Photoshop PSD files, is to beware of only saving copies of your work in an application-specific file format. Thankfully, I was able to extract the artwork by opening it in Affinity Designer then exporting as PNG.