We are now using mrviewer as our base image sequence player in our company. It fits very well in our nuke-based image pipeline, because it supports proper viewing of our exr images, and has option to convert custom luts like .cube or .3dl. to its ctl format and use it. Great for viewing quicktimes also, you can even continuously zoom into those. We are also using it to check shots in the cut, because it can load (custom) edls. And it can do a lot other, the feature list is very long. The player is very fast, lightweight, and very frequently updated with new features. The developer is extremely responsive and helpful, helped us in every feature request we came up with, and did it very fast. I think this player is much better than the other free alternative djv_view. And it's getting better and better.