Being a Microsoft software developer is a lot like ordering breakfast at the International House of Pancakes. You get a stack of pancakes with every dish and you must choose from a variety of pancakes and syrup flavors. For web applications, a solution stack is a set of software subsystems or components needed to deliver a fully functional solution, be it a product or a service. To develop a web application for example, the Microsoft developer needs to use and understand the Microsoft Stack of components including the ever emerging set of open source tools, design patterns and 3rd party products. That's a lot of pancakes.