Nomacs for Windows, Linux, FreeBSD, Mac, and OS/2.

[Abarbarian]

nomacs is a free, open source image viewer, which supports multiple platforms. You can use it for viewing all common image formats including RAW and psd images.

Nomacs

I use this on my Arch and it is the quickest to open and use photo program I have found. I did use PhotoQt which is pretty quick and I prefer it to nomacs as I like the way it is set up but it borked on me and I can not be bothered fixing it at the moment.

 

[Abarbarian]

Nomacs is plain looking but it has some neat features.

To enlarge the photo you use the scroll wheel which is pretty standard. The tilt function on my mouse takes you to the next picture or the previous one.
The thumbnails bar at the top can be removed to give more space for the pictures. What is neat about the thumbnails is you only have to hover the mouse over them for them to scroll back and forward, no clicks needed.

 

[Abarbarian]

Another feature I like is pressing "Shift + T" gives you this,

Clicking on an individual picture opens it up.Certainly makes my life easier as I use tux pictures as icons in my Window Maker set up and this is the easiest way I have found to search the few tux pictures I have on file.

They say one of the drawbacks of linux is too much choice. I have to agree it is a real pain in the butt choosing a new tux picture for an icon when called to do so. All that wasted time could be put to much better use I am sure.