This is a truly impressive resource for comparative national statistics across a broad range of topics. Here's what developer Luke Metcalfe says about the site:
The idea for NationMaster arose as I was surfing around the CIA World Factbook. It's a great read but I felt the individual figures (like number of TV's, or kilometres of coastline) didn't mean much on their own. They'd be more illuminating if they were placed alongside other countries and shown relative to population.
So I decided to put together a website that allowed users to generate graphs based on numerical data extracted from the Factbook. The next (rather obvious) realization was that there's no reason I couldn't take in data from other sources. Why shouldn't the net have a central location that allows you to compare countries on any statistic you like?
But why did I do it? To promote education and understanding about the world. To make it easy to engage with the indicators that shape global commerce, health, politics and ecology. To make the facts easily accessible and meaningful. To bring the works of academics, public agencies and private researchers to a wider audience.
One intended use for this site is, during debates in discussion groups, people link to comparisons of specific countries. I hope students, educators and librarians will find the site a useful teaching aide. More generally, I hope the figures will spark people's interest and they'll want to read more.