In computing, a solution stack or software stack is a set of software subsystems or components needed to create a complete platform such that no additional software is needed to support applications. Applications are said to "run on" or "run on top of" the resulting platform. Some definitions of a platform overlap with what is known as system software.
For example, to develop an IT solution; in the case of a web application the architect defines the stack as the target operating system, web server, database, and programming language. Another version of a solution stack is operating system, middleware, database, and applications. Regularly, the components of a solution stack are developed by different developers independently from one another.
Some components/subsystems of an overall system are chosen together often enough that the particular set is referred to by a name representing the whole, rather than by naming the parts. Typically, the name is an acronym representing the individual components.