I can understand the use of BMP, since it is a simple RAW format, commonly used for icons and small images.

However, I can not understand why JPG has not been added yet. The code is free to use for "Viewing", and I think it is now free to use for "Saving", just like GIF.

This is a major file-size saver. Not to mention, it allows online files to be included in the program. (Yes, you can put BMP online also, but sending a BMP, due to size, is a waste of bandwidth.)

For the UI, there should be a standard IMG control. IMGBMP, IMGJPG, IMGGIF, each with the ability to be... scaled within dimensions, stretched to dimensions, fixed size, clickable (additional DOWN image), selectable (additional SELECTED image), and maskable (additional color-mask image, on color of 2-256 or full color, possibly with future ability for full 256 shade masking.)

I would suggest PNG, but there is no advantage to that horrible format. (Not file-size wise, except over BMP. Since PNG is just layers of BMP's, without a real standard, it is complex to handle them correctly when they use multiple layers. But that would make a great future toy.)