The font is Open Sans, a free sans-serif font with a large range of glyphs.
This site is best viewed with a CSS 3-compliant browser. All pages should be XHTML 1.0 strict / CSS 3.0 compliant. If they are not, it is a bug, and please report it to me. You can validate the pages by clicking on the "XHTML 1.0 Strict" and "CSS 3.0" texts at the bottom.