Splenda

is made of sucralose and maltodextrin.
(In response to Tanya’s question in the comments to this post on her site.)
We eat it all the time, primarily on rice (with cinnamon). Basically it’s sugar with the carbohydrates removed. I think the maltodextrin is there primarily to give the sucralose bulk, and given that it’s only 4 calories per gram, there can’t be much of it in Splenda. Sucralose, derived from sucrose, is the actual sweetner, as the FAQ points out:

How is SPLENDAョ Brand Sweetener made?
SPLENDAョ is the brand name for the ingredient sucralose. It is made through a patented, multi-step process that starts with sugar and converts it to a no calorie, non-carbohydrate sweetener. The process selectively replaces three hydrogen-oxygen groups on the sugar molecule with three chlorine atoms. Chlorine is present naturally in many of the foods and beverages that we eat and drink every day ranging from lettuce, mushrooms and table salt. In the case of sucralose, its addition converts sucrose to sucralose, which is essentially inert. The result is an exceptionally stable sweetener that tastes like sugar, but without sugar’s calories. After consumption, sucralose passes through the body without being broken down for energy, so it has no calories, and the body does not recognize it as a carbohydrate.

Also:

How was the safety of SPLENDAョ Brand Sweetener determined?
More than 100 scientific studies on sucralose conducted over a 20-year period have demonstrated the safety of SPLENDAョ Brand Sweetener. The data from these comprehensive studies were independently evaluated by the FDA and international experts in a variety of scientific disciplines. The safety of sucralose has also been confirmed by years of both domestic and international use.

And I see that the complaints about sucralose and Splenda sound very much like the ones about saccharin and other artificial sweetners. So Splenda is probably dangerous to your health if you drink 400 chocolate shakes per day sweetened with it. You can read the report at Junkscience.com; I won’t waste my time posting links to the detractors, you can find them yourself with a quick Google search.