This is a screenshot from a mod called TerrafirmaCraft. This mod is a major overhaul of the minecraft system, trying its best to make gameplay more realistic. Want wood? You can't punch trees with your bare hands. You have to make a stone axe first. Stones scattered along the ground can be shaped into a few basic tools for this purpose.
The terrain generation is much more realistic as well, as can be seen here. These look like actual islands you would find in a major ocean.
If you're wondering, the red bar is health, green bar is hunger and blue bar is thirst.
Picture Added December 9, 2012, 10:49:09 AM (-08:00)
Added by Shade