>Also TIFF is an open container like MKV and can be used for far more than just simple pictures.

I see this commonly in different business and medical applications where information may need to be accessible for years or decades after creation. There is a pretty even mix of TIFF and PDF/A in these environments and because of the legal liabilities I don't see them being displaced.

Not to mention TIFF supports layers. From a skim of the homepage, this doesn't.

FLIF allows for animation, and it is very possible to interpret each frame of the animation as it's own layer. This would year the same lossless quality as a TIFF at a much smaller file size. Though FLIF isn't intended to be used for this purpose, neither was PNG, and that didn't stop Fireworks from abusing that format and adding layering. The same could be done by someone who wants to add a little meta data to the file to let layered flif opening applications know that the frame are to be interpreted in that manner.

This format isn't complete yet, if layering is important to you, you should join the gitter.im/FLIF-hub/FLIF chat room.

A bigger question here is why not build FLIF as a document format using an established container? Why not use something established, mainstream and non controversial like TIFF as the container and FLIF as the codec. I'm kind of sick of this "new file format and file extension for no good reason" crap. MKV as a container and I dont care about codec because FFMPEG/VLC/etc support all the codecs is great, it hides all the complexity and enables codec experimentation without hassle. FLIF is an image encoding/decoding scheme that would be completely compatible inside a TIFF image if implemented correctly.

Why do I care about having a "dot flif" file when the new codec is the important improvement?

Is '*.flif' actually a good thing?

Personally I don't think so, mainly because without a mechanism to drive adoption in browsers, the format offers very little value to anyone over existing formats. TIFF would be a decent solution to that problem. ... And the fact that FireFox has marked TIFF support as WONTFIX is actually pretty indicative of how unlikely they are to support a new format such as FLIF. Sad but true. From what I already see of the FireFox support thread for FLIF, its not going to happen any time soon.