Runtimes

• What is a Runtime ?

  It's a generally used term for runtime system. runtime (= runtime system) is different from "Run time".

• What is a Run time ?

  Run time is a phase of a computer program in which the program is run or executed on a computer system. Run time is part of the program life cycle, and it describes the time between when the program begins running within the memory until it is terminated or closed by the user or the operating system. Run time is also known as execution time.

• What is a Runtime System ?

  A runtime system is an engine that generally performs these functions for other programs

  • Garbage collection

  • Stream input/output

  • Structured input/output

  • Process suspension

  • Operating System Calls

  • Handling interrupts and asynchronous events

  • Handling arithmetic exceptions

  • Assembly language implementation of language primitives

  • Foreign language procedure calls

  • Execution profiling

  • Debugging

    For nice detailed perspective, you should read this paper by Andrew D Appel:

• What is an engine ?

  In computer programming, an engine is a program that performs a core or essential function for other programs. Engines are used in operating systems, subsystems or application programs to coordinate the overall operation of other programs. The engine must be running in the computer in order for those other programs to use its functions.

• What is a Runtime Library:

  The runtime library is primarily the software/programming component of a runtime system. Typically, it consists of many different programs or functions that are commonly used in various programs. These include I/O routines, graphical functions, mathematical functions and more. The runtime library is invoked in all programs. At program runtime, the respective runtime library or function is loaded in the memory until the primary program has finished execution or no longer requires that function.

• What is a Runtime Environment:

  Runtime environment is a state of the target machine, which may include the environment variables, CPU registers, memory resources, operating system, runtime systems and system software required by a particular category of applications. Distinguish this from Development Environments and Build Environments:

  • Run time environment: Everything you need to execute a program, but no tools to change it.

  • Build environment: Given some code written by someone, everything you need to compile it or otherwise prepare an executable that you put into a Run time environment. Build environments are pretty useless unless you can see tests what you have built, so they often include Run too. In Build you can't actually modify the code.

  • Development environment: Everything you need to write code, build it and test it. Code Editors and other such tools. Typically also includes Build and Run.