Richard Gill encouraged me to install on CTAN a copy of his and J C Loredo's prodint font. I have now done so.
from the catalogue entry i have just written:
Product integrals are to products, as integrals are to sums. They have been around for more than a hundred years, they have not become part of the standard toolbox, possibly because no-one invented the right mathematical symbol for them. The authors remedied that situation by proposing the symbol and providing this font.
Users may view the package's catalogue entry at http://www.tex.ac.uk/tex-archive/help/Catalogue/entries/prodint.html or browse the package's directory at http://www.tex.ac.uk/tex-archive/fonts/prodint/
The catalogue entry will appear for the first time when my processing runs overnight tonight.
Robin Fairbairns
For the CTAN team