It's a very common font in mathematical texts or formulas. I think it's also the font used in Wikipedia's formulas, such as in the page
http://en.wikipedia.org/wiki/Integral_calculusIdentified font
Euclid Suggested by claudeserieux Euclid of Design Science (Mathtype)
Edited on Oct 06, 2010 at 10:24 by Rodolphe
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