ISOMALT is a mixture of two disaccharide alcohols—gluco-mannitol and gluco-sorbitol. Sucrose, by comparison, is a disaccharide sugar, gluco-fructose. IMO, it's not too sweet and has to be used in high quantities (just like sugar). It's not exactly the same as splenda, but the same concept.
Thanks!! I was wondering what it was. The ingredient list for the candy has the serving listed as 4 pieces (they are sugar free) for 25 cals, 13g isomalt & 13g carb.