Managed code is computer program code that requires and will execute only under the management of a

Common Language Infrastructure The Common Language Infrastructure (CLI) is an open specification and technical standard originally developed by Microsoft and standardized by ISO/ IEC (ISO/IEC 23271) and Ecma International (ECMA 335) that describes executable code and a ...

(CLI);

Virtual Execution System The Virtual Execution System (VES) is a run-time system of the Common Language Infrastructure CLI which provides an environment for executing managed code. It provides direct support for a set of built-in data types, defines a hypothetical machi ...

(VES);

virtual machine In computing, a virtual machine (VM) is the virtualization/ emulation of a computer system. Virtual machines are based on computer architectures and provide functionality of a physical computer. Their implementations may involve specialized har ...

, e.g. .NET, CoreFX, or

.NET Framework The .NET Framework (pronounced as "''dot net"'') is a proprietary software framework developed by Microsoft that runs primarily on Microsoft Windows. It was the predominant implementation of the Common Language Infrastructure (CLI) until bein ...

;

Common Language Runtime The Common Language Runtime (CLR), the virtual machine component of Microsoft .NET Framework, manages the execution of .NET programs. Just-in-time compilation converts the managed code (compiled intermediate language code) into machine instruc ...

(CLR); or Mono. The term was coined by

Microsoft Microsoft Corporation is an American multinational corporation, multinational technology company, technology corporation producing Software, computer software, consumer electronics, personal computers, and related services headquartered at th ...

. Managed code is the compiler output of

source code In computing, source code, or simply code, is any collection of code, with or without comment (computer programming), comments, written using a human-readable programming language, usually as plain text. The source code of a Computer program, p ...

written in one of over twenty high-level

programming languages A programming language is a system of notation for writing computer program, computer programs. Most programming languages are text-based formal languages, but they may also be visual programming language, graphical. They are a kind of computer ...

, including C#, J# and Visual Basic .NET.

Terminology

The distinction between managed and unmanaged code is prevalent and only relevant when developing applications that interact with CLR implementations. Since many older programming languages have been ported to the CLR, the differentiation is needed to identify managed code, especially in a mixed setup. In this context, code that does not rely on the CLR is termed "unmanaged". A source of confusion was created when Microsoft started connecting the .NET Framework with C++, and the choice of how to name the

Managed Extensions for C++ Managed Extensions for C++ or Managed C++ is a now-deprecated set of language extensions for C++, including grammatical and syntactic extensions, keywords and attributes, to bring the C++ syntax and language to the .NET Framework. These extension ...

. It was first named Managed C++ and then renamed to

C++/CLI C++/CLI is a variant of the C++ programming language, modified for Common Language Infrastructure. It has been part of Visual Studio 2005 and later, and provides interoperability with other .NET languages such as C#. Microsoft created C++/CLI ...

. The creator of the C++ programming language and member of the C++ standards committee,

Bjarne Stroustrup Bjarne Stroustrup (; ; born 30 December 1950) is a Danish computer scientist, most notable for the invention and development of the C++ programming language. As of July 2022, Stroustrup is a professor of Computer Science at Columbia Universit ...

, even commented on this issue, "On the difficult and controversial question of what the CLI binding/extensions to C++ is to be called, I prefer C++/CLI as a shorthand for "The CLI extensions to ISO C++". Keeping C++ as part of the name reminds people what is the base language and will help keep C++ a proper subset of C++ with the C++/CLI extensions."

Uses

The

Microsoft Visual C++ Microsoft Visual C++ (MSVC) is a compiler for the C, C++ and C++/CX programming languages by Microsoft. MSVC is proprietary software; it was originally a standalone product but later became a part of Visual Studio and made available in both tr ...

compiler can produce both managed code, running under CLR, or unmanaged binaries, running directly on Windows. Benefits of using managed code include programmer convenience (by increasing the level of abstraction, creating smaller models) and enhanced security guarantees, depending on the platform (including the VM implementation). There are many historical examples of code running on virtual machines, such as the language

UCSD Pascal UCSD Pascal is a Pascal programming language system that runs on the UCSD p-System, a portable, highly machine-independent operating system. UCSD Pascal was first released in 1977. It was developed at the University of California, San Diego (UC ...

using

p-code Bytecode (also called portable code or p-code) is a form of instruction set designed for efficient execution by a software interpreter. Unlike human-readable source code, bytecodes are compact numeric codes, constants, and references (normal ...

, and the operating system

Inferno Inferno may refer to: * Hell, an afterlife place of suffering * Conflagration, a large uncontrolled fire Film * ''L'Inferno'', a 1911 Italian film * ''Inferno'' (1953 film), a film noir by Roy Ward Baker * ''Inferno'' (1973 film), a German ...

from

Bell Labs Nokia Bell Labs, originally named Bell Telephone Laboratories (1925–1984), then AT&T Bell Laboratories (1984–1996) and Bell Labs Innovations (1996–2007), is an American industrial research and scientific development company owned by mult ...

using the Dis virtual machine.

Java Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's mo ...

popularized this approach with its

bytecode Bytecode (also called portable code or p-code) is a form of instruction set designed for efficient execution by a software interpreter. Unlike human-readable source code, bytecodes are compact numeric codes, constants, and references (norma ...

executed by the

Java virtual machine A Java virtual machine (JVM) is a virtual machine that enables a computer to run Java programs as well as programs written in other languages that are also compiled to Java bytecode. The JVM is detailed by a specification that formally describ ...

Google Google LLC () is an American Multinational corporation, multinational technology company focusing on Search Engine, search engine technology, online advertising, cloud computing, software, computer software, quantum computing, e-commerce, ar ...

also mention

and Kotlin are managed code in their Android NDK JNI documents

References

{{Reflist

External links

Microsoft Research OS written in managed C# code
Channel 9 .NET terminology