Software that must be running in the computer for applications to execute. For example, all programming language interpreters are runtime engines. They convert the program, which is in its original source code or which has been converted into an interim, intermediate language, into machine language. In addition, runtime engines provide common routines and functions that the applications require.
Although not classified as such, one might call an operating system a runtime engine because it is always required. Indeed, it "is" the essential runtime engine; however, the OS falls into the "runtime environment" category.
Runtime Engine Examples
A JavaScript runtime engine is part of every Web browser. Java programs (not the same as JavaScript) require the Java Virtual Machine in order to run. In a Windows PC, Visual Basic programs require the VB runtime module VBRUNxxx.DLL (xxx is the version number). Microsoft's .NET platform uses the Common Language Runtime (CLR) engine to compile .NET applications into machine language (see
CLR). See
JavaScript,
Java,
Visual Basic,
CLR,
managed code,
runtime library,
runtime version and
runtime environment.