Risa,
Worcestershire Sauce traditionally has tamarind. I'm sure it's like any other sauce, ie spaghetti sauce, chili paste, BBQ sauce, etc. They're all a little different just as there are different companies who Worcestershire Sauce and each adds their own "flare"...
Here is a recipe you may enjoy:
Worcestershire Sauce
2 tablespoons olive oil
2 large onions, roughly chopped
1/2 cup tamarind paste
2 tablespoons minced garlic
2 tablespoons minced ginger
2 jalapenos seeds removed, minced
3 tablespoons chopped anchovies
3 tablespoons tomato paste
2 whole cloves
2 tablespoons freshly cracked black pepper
1/2 cup dark corn syrup
1 cup molasses
3 cups white vinegar
1 cup dark beer
1/2 cup orange juice
2 cups water
1 lemon thinly sliced
1 lime thinly sliced
In a large saucepan, heat the olive oil over medium heat. Add the onion and saute until soft, about 6 to 7 minutes. Stir in the tamarind paste,garlic, ginger, and jalapenos and cook for 5 more minutes. Add the anchovies, tomato paste, cloves, pepper, corn syrup, molasses, white vinegar, dark beer, orange juice, water, lemon and lime. Bring to a boil, reduce heat to medium low, and simmer, stirring occasionally, for 2 to 3 hours, or until it naps the back of a spoon. Strain the mixture and refrigerate.