Home > Articles > Programming > Windows Programming

  • Print
  • + Share This
Like this article? We recommend

Like this article? We recommend

.NET Framework Architecture (CLR)

Microsoft's .NET Framework provides an amazing aspect of development, called cross-language development, which includes cross-language inheritance, cross-language debugging, and cross-language exception handling. More generally, we can visualize cross-language development as follows. Code written using any .NET-compliant language (such as C#) should be usable in any other .NET-compliant language (such as VB). Later on, these code modules should be usable in yet another language (such as JScript, J#, and so on). To make this possible, you need a common runtime environment that can understand all these languages.

One of the main design goals of .NET is to encourage cross-language development. The advantage is that the developer can choose the language that best suits for delivering a given module/unit (each language has its own strengths) and still be able to integrate into a single application. The end result is that the language becomes equal. Even employers feel more comfortable with cross-language development, as they have more resources and options at hand.

The .NET Framework also eliminates "DLL hell" and allows for side-by-side deployment of components because registration information and state data are no longer stored in the Registry, where this information can be difficult to establish and maintain.

Next, let's explore the cross-language capabilities of CLR (the Common Language Runtime Environment) and see how IL (Intermediate Language) becomes the core of all .NET-compliant languages. In particular, I'll discuss how to program for the CLR and show some examples that demonstrate the cross-language capabilities of the .NET Framework.

Common Language Runtime

The Common Language Runtime (CLR) Environment provides a rich set of features for cross-language development and deployment. CLR supports both object-oriented languages and procedural languages. CLR manages the execution of code and provides various services such as security, garbage collection, cross-language exception handling, cross-language inheritance, support for the Base Class Library (BCL), and so on. These are the main constituents of the CLR:

  • The Common Type System (CTS) supports object-oriented programming languages as well as procedural languages. Basically CTS provides a rich type system that's intended to support a wide range of languages.

  • The Common Language Specification (CLS) is a subset of the Common Type System, to which all language compilers targeting CLR must adhere.

  • All compilers under .NET will generate a uniform, common language called Intermediate Language (IL), no matter what language is used to develop the application. In fact, CLR will not be aware of the language used to develop an application. For this reason, IL can be considered the language of CLR—a platform for cross-language development.

  • The Just in Time (JIT) compiler converts the Intermediate Language code back to a platform/device-specific code. In .NET you have three types of JIT compilers:

  • Pre-JIT (compiles entire code into native code at one stretch)

  • Ecno-JIT (compiles code part by part, freeing when required)

  • Normal-JIT (compiles only that part of the code when called, and places it in the cache)

  • Type safety is ensured in this phase. In all, the role of a JIT compiler is to bring higher performance by placing the once-compiled code in cache, so that when the next call is made to the same method/procedure, it's executed at a faster speed.

  • The Virtual Execution System (VES) implements the Common Type System. VES loads links and runs Portable Executable (PE) files. VES also ensures loading of the information contained in metadata.

  • Metadata describes and references the datatypes defined by the VOS type system, lays out instances of classes in memory, resolves method invocation, and solves versioning problems (DLL hell).

Figure 1 depicts the .NET architecture.

Figure 1 .NET architecture.

The Windows operating systems run on the Intel family of microprocessor chips. To generate platform-neutral code, two things should happen:

  • Elimination of hardware dependencies such as microprocessor instruction sets, etc.

  • Elimination of software dependencies such as operating-system-naïve API, etc.

Once the code is compiled using any of the .NET-compliant language compilers, it gets converted to IL (Intermediate Language), as shown in Figure 1. This code is not compiled to machine-native code, but to an intermediate form that doesn't contain any specific information about hardware or software dependencies. When you run this code, since it's not in machine-specific form, it fails to execute. A runtime environment is required that understands and converts the IL code to machine-specific code. This is the role played by CLR (along with the many other functions discussed earlier). I won't talk about these issues in detail here, but will instead concentrate on implementation of cross-language capabilities of the .NET Framework.

Common Language Features

  • All languages use the same library, the Base Class Library (BCL). However, the syntax used by these languages remains the same as that of the original language.

  • No language under .NET has its own library.

  • Garbage collection is the responsibility of the CLR environment and not a language.

  • + Share This
  • 🔖 Save To Your Account

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information

To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.


Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.


If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information

Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.


This site is not directed to children under the age of 13.


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information

If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.


Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information

Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents

California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure

Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact

Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice

We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020