Ice Cream comes in all flavors now a days and one of the most known flavors is pistachio.  This flavor comes from the pistachio nut wich is like a cachew and it's green, this is the source of this flavored ice cream unique color.  The creator of the pistacho is cream is known as James Woods Parkinson around 1940.  James Woods is a american cook based in Philadelphia around the 1940's and thanks to him the Philadelphia ice cream became famous in the 20th century.  But there is a diference with this ice cream and the modern day recipe.  For someone to understand, you have to know first that there are two styles of ice cream making.  This are the Philadelphia style, which has no milk and is prepared diferently and the French style which is known today as the modern day ice cream, this style contains milk and that is the main diference between the Philadelphia and the French style.  The modern day pistachio is made this way with every company diferencing on the amount of nuts and diferent ingredients added.  But at the end of the day, pistachio ice cream will almost always taste the same.  

- Marcos