The core font family is Ariel. The majority of text within the site is Ariel. Regular, bold, italics and underlined are all acceptable ways to use the font. Occasionally Times New Roman is used as an accent font. HIMSS also uses the following for artistic visual appeal: Rotis Semi-sans, Tainted, Optima. These fonts are only found in graphical images, not as web based text.
The chart below details the font, color and size for text within the HIMSS.org website