TL;DR; I've made a polyfill for CSS3 Object-fit. Download it from Github here: https://github.com/steveworkman/jquery-object-fit
The need for object-fit
A month ago, I was looking into creating a responsive grid full of images for a client. The width of the columns would vary depending upon device, and the dimensions and aspect ratio of the provided images could not be guaranteed.
The issue for me is keeping the images looking great, without skewing the dimensions and distorting the results, but I also needed them to expand or shrink to fit the boxes that they had been provided with.
Knowing CSS, the property
background-size: cover|contain would do this perfectly (See this A List Apart article for lots more detail), but this is for background images, and semantically, the images in my grid are part of the content, so should not be background images. Looking for an equivalent, I found Object-fit: part of the CSS3 Image Values and Replaced Content spec. Unfortunately, browser support for this is very poor; this is the current browser implementation of this property: