Vinyl Ester, or Vinylester, is a resin produced by the esterification of an epoxy resin with an unsaturated monocarboxylic acid. The reaction product is then dissolved in a ...
http://en.wikipedia.org/wiki/Vinyl_ester

Epoxy Resin vs. Vinylesters and Polyesters. Here's a different way to look at epoxy resin vs. vinylester resin as was explained to me by an R & D chemist named Mike Daniels.
http://www.redrockstore.com/resin.htm

is a Prepreg manufacturing company, the first in the Middle-East, using epoxy vinyl ester resins and all kind of reinforcement fabrics (i.e. glass, carbon and aramid fibers
http://www.gulfcomposite.com/

... Nylon and Grafted Thermoplastic Polymers, and our Equipment Grouts in Cementitious (GT 100NS) Epoxy (GT 3000 and GT 5000), GT 4500 (Epoxy Novolac) & GT 4000 (Vinyl Ester).
http://vinylester.com

Fiberglass Warehouse is a leading supplier of fiberglass, polyester and epoxy resins, mold releases, gelcoats, adhesives, mold making materials, cores, foam, and many more products
http://www.fiberglasswarehouse.com/vinylester_resin.asp