It could have been a backwards compatible extension to GIF instead.<p>More formats = fragmentation = consumer confusion and problems.<p>Progress is not a single variable either, there are plenty of ways that you can define progress that are more or less orthogonal to each other.<p>Forward, sideways and 'up' are all movements that you can interpret as 'progress' depending on where you are and where you want to be.<p>From that point of view PNG was sideways and 'around' rather than forward.<p>Any kind of dataformat, any kind of protocol, anything that is not a completely closed box that performs a function (an 'appliance') should be as open as possible.<p>And that should be enshrined in law, interfaces and formats are automatically in the public domain, and have to be documented.<p>PNG as a GIF replacement is superior, for most applications. But if you think in terms of browser support then you could interpret it as a step back during the introduction phase as well.