Click here to close now.


Microsoft Cloud Authors: Jayaram Krishnaswamy, Elizabeth White, Andreas Grabner, Jim Kaskade, Pat Romanski

Related Topics: Microsoft Cloud

Microsoft Cloud: Article

The Myth of .NET Purity

The Myth of .NET Purity

There is an increasing amount of discussion around the topic of ".NET Purity" in development circles. When selling an application the question often arises "is your application 100% .NET?" or "How much of your application is .NET?" There is an implied qualitative judgment behind these questions and it's usually pejorative.

The implication is that an application that is entirely written in .NET, presumably without any interoperation with COM or direct calls to the Win32 API, is superior to an application that is a combination of technologies.

Certainly .NET represents a fantastic leap in developer productivity and puts a clean, consistent face on the services that the Windows Platform provides. For many years the set of interfaces provided by the Windows OS Platform - collectively known as the Windows SDK - have been exposed to developers as exported "C"-style functions in DLLs, and in recent years, via the Component Object Model (COM).

Common Language Runtime or Virtual Machine?
Often the .NET Common Language Runtime, or CLR, is directly compared to the Java Virtual Machine. Initially, there are many clear parallels: both are "managed" environments that provide a component container, both consume a "partially chewed" intermediate language, both provide low-level services like garbage collection and threading conveniences.

While these parallels are superficially compelling, these two implementations differ fundamentally in philosophy. Comparing the CLR to the VM is reasonable only to a certain point - their architectural goals are ultimately different.

Sun promotes a marketing program called 100% Pure Java, which is certainly appropriate if code portability and underlying operating system transparency is a desirable endpoint. However, many 3rd party Java Application Servers create a competitive advantage by judicious use of "C" function calls directly down (via Java Native Interface or JNI) into their host Operating Systems value-added services that are not exposed by the Java Application Platform (the Java Class Library). Calling into the core platform is the only way to make use of base functionality that is only presented via a native interface!

The Java VM is truly a "virtual machine" that's ultimate goal is to abstract (virtualize) away the underlying Operating System and provide an idealized (not necessarily ideal, but idealized) environment for development. The Java Virtual machine is also intimately united with the API - the Java Application Platform, which services provided by the VM implementation. Regardless of where you run your compiled Java code, you will run within the context of the Virtual Machine and ostensibly link with supplied Java Platform APIs.

The .NET Common Language Runtime is named well as it is used more as a Language Runtime than a Virtual Machine. While it successfully abstracts away aspects of underlying hardware through its use of an Intermediate Language, when the CLR is combined with the .NET Framework Library of APIs it is married to the underlying platform, which is Windows. The CLR provides all the facilities of the Windows Platform to any .NET-enabled Language.

.NET Framework Library
The Windows Platform has dozens and dozens of high-level system services that are exposed by thousands of APIs. This large library of functionality encompasses various levels of richness. A low-level API may open a file off a disk, while a high-level one might play an audio file. The designers of the .NET Framework wanted to create a consistent object-oriented face on a rich legacy of platform functionality. The CLR and .NET Framework work together to expose the capabilities within the Windows Platform, including those that may have previously been hidden away in difficult or little known APIs.

While the CLR provides a new paradigm for application development, it does not close the door on existing libraries. The CLR provides interop services to the developer but the biggest consumer of these services are the .NET Class Libraries that unlock existing Windows Platform abilities via a .NET API!

For example, when sending email using the .NET Framework Library class System.Web.Mail.SmtpMail, the Class Library uses a helper class that abstracts the existing CDO (Collaboration Data Objects) COM Library. This is just one example where a .NET Library developer chose to rely on a production-ready reliable existing library rather than write something from scratch. This example and dozens of others with the Library not withstanding, the Common Language Runtime still at some point needs to work with the Windows internal APIs.

If Microsoft were to truly virtualize the machine, they would have marginalized their investment in the Windows platform. Certainly it behooved the designers to make transitions to existing libraries as painless as possible. They have enabled this with NET » COM Interop via both Runtime- and COM-Callable Wrappers, the ability to tap into standard Win32 Platform APIs via a technology called P/Invoke (short for Platform Invoke) as well as other options. When writing code that is hosted in the CLR the vast resources of platform are just sitting under the developer - the runtime is transparent rather than virtual! This marks a fundamentally different view of the platform that other virtualizing machine implementations.

While creating a new fresh application using only .NET may offer some benefits in the arenas of deployment or marketing, these benefits may be not realized when weighed against the cost of rewriting non-.NET components in .NET when those legacy components could have been leveraged. A "pure" .NET solution can only make use of either those pieces of functionality that can be achieve entirely within the runtime, or those functions that have been exposed by the Base Class Library - which itself uses COM Interop and P/Invoke!

The .NET Framework Library itself isn't "pure .NET" as it takes every opportunity to take full advantage of the underlying platform primitives. Moreover, the concept of .NET Purity is rendered specious in this new light. The .NET Framework is the best way to create business components on the Windows Platform, but any applications along with the .NET Framework are only lifted as high as the underlying Windows OS services.

"Hybrid" Solutions provide Real Solutions
Many large existing applications are written in Visual C++ and COM. They are written "close to the metal" to take full advantage of native Windows multi-threading and fine-grained memory management. However, new business components may also be written in a .NET language such as C# or VB.NET. The existing system then hosts the .NET Common Language Runtime within its process space and Interops. The interface is usually COM interop but only incurs minimal overhead of between 10 and 40 processor instructions per in-proc call.

.NET Components hosted with in the legacy applicaiton can take advantage of that application's existing services. Lower level developer features such as memory management, object lifetime and object orientation are provided by the CLR, while higher level vertical-specific business functionality is exposed via the legacy application.

This "hybrid" can provide a best-of-breed solution on the Windows Platform exploiting both the highly performant low-level APIs via C++ and the highly componentized and object oriented features of the .NET Framework. These solutions can work very successfully while companies migrate their existing code bases to the .NET Framework.

More Stories By Scott Hanselman

Scott Hanselman will be starting a new job at Microsoft as a senior program manager in the developer division. His blog is at

Comments (4) View Comments

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.

Most Recent Comments
Tim Huckaby 07/25/03 07:07:00 PM EDT

Your comments on are interesting. Adsi is simply a com wrapper, so technically it?s a ?wrapped wrapper? of the native ldap api which, of course, is c++ only. Being that said, the directory entry class you are referring to is a ?wrapped, wrapped wrapper?. Ultimately, the big disappointment of the .net framework 1.1 and the hope for 2.0 is more native framework classes.

Derek Ferguson 07/18/03 10:12:00 AM EDT

I would never suggest that COM Interop should be gotten rid of or is in any way, shape, or form "evil." However, as a developer who spends more than 90% of my coding time working with the System.DirectoryServices and System.Management namespaces, let me tell you -- MS could have save developers a lot of gried by having written some managed protocol handlers here, rather than just wrapping up the old, troubled API's.

As one example of this, the DirectoryEntry class in System.DirectoryServices allows you to pass a username and password to its constructor. However, when you use the WinNT ADSI provider, these parameters are sometimes ignored. Why is this? Because of a limitation in the existing API's that were wrapped!

Similar problems abound in the System.Management namespace -- where I recently managed to prove that Impersonation (a native API) interacts differently with EnablePrivilieges (a wrapped API) under ASP.NET than it does under the Console. In working through this with MS, I have been passed around to 10 different people in their Support infrastructure. Why? Because the old, obscure API's that have been wrapped are a "dark art" that are only known by a few individuals within the Redmond infrastructure.

Once again: it would've been better to have recreated the whole thing in C#.

Dean Guida 07/25/03 04:00:00 PM EDT

There is a lot to be said for purity for purity's sake. I have never subscribed to this type of thinking. At the end of the day we all want to build dependable software that solves the business problem at hand. Everything should always be taking in context of a solution with a sense of practicality. I think most of the software development community has this maturity.

Patrick Hynds 07/17/03 10:16:00 PM EDT

I think this article is right on, but felt that we should confront the issue of why this kind of rebuttal is needed (and it is needed). We find people who are earnest only in so far as they can justify their existence. Therefore they brand something heresy as soon as they abandon the practice themselves. Lets assume that COM interop was a horrible waste of resource, it still wouldn't justify discarding a tool and the wealth of existing functionality the last generation always holds in such a wholesale manner. I have seen people in ASP circles a while back declare that "Session State is bad". Like hybrid applications Session State in ASP is a tool, use it, don't use it, but if you happen to need a hammer it doesn't make the saw evil.

@ThingsExpo Stories
SYS-CON Events announced today that IBM Cloud Data Services has been named “Bronze Sponsor” of SYS-CON's 17th Cloud Expo, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. IBM Cloud Data Services offers a portfolio of integrated, best-of-breed cloud data services for developers focused on mobile computing and analytics use cases.
In his session at @ThingsExpo, Tony Shan, Chief Architect at CTS, will explore the synergy of Big Data and IoT. First he will take a closer look at the Internet of Things and Big Data individually, in terms of what, which, why, where, when, who, how and how much. Then he will explore the relationship between IoT and Big Data. Specifically, he will drill down to how the 4Vs aspects intersect with IoT: Volume, Variety, Velocity and Value. In turn, Tony will analyze how the key components of IoT influence Big Data: Device, Connectivity, Context, and Intelligence. He will dive deep to the matrix...
When it comes to IoT in the enterprise, namely the commercial building and hospitality markets, a benefit not getting the attention it deserves is energy efficiency, and IoT’s direct impact on a cleaner, greener environment when installed in smart buildings. Until now clean technology was offered piecemeal and led with point solutions that require significant systems integration to orchestrate and deploy. There didn't exist a 'top down' approach that can manage and monitor the way a Smart Building actually breathes - immediately flagging overheating in a closet or over cooling in unoccupied ho...
Scott Guthrie's keynote presentation "Journey to the intelligent cloud" is a must view video. This is from AzureCon 2015, September 29, 2015 I have reproduced some screen shots in case you are unable to view this long video for one reason or another. One of the highlights is 3 datacenters coming on line in India.
“The Internet of Things transforms the way organizations leverage machine data and gain insights from it,” noted Splunk’s CTO Snehal Antani, as Splunk announced accelerated momentum in Industrial Data and the IoT. The trend is driven by Splunk’s continued investment in its products and partner ecosystem as well as the creativity of customers and the flexibility to deploy Splunk IoT solutions as software, cloud services or in a hybrid environment. Customers are using Splunk® solutions to collect and correlate data from control systems, sensors, mobile devices and IT systems for a variety of Ind...
SYS-CON Events announced today that ProfitBricks, the provider of painless cloud infrastructure, will exhibit at SYS-CON's 17th International Cloud Expo®, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. ProfitBricks is the IaaS provider that offers a painless cloud experience for all IT users, with no learning curve. ProfitBricks boasts flexible cloud servers and networking, an integrated Data Center Designer tool for visual control over the cloud and the best price/performance value available. ProfitBricks was named one of the coolest Clo...
You have your devices and your data, but what about the rest of your Internet of Things story? Two popular classes of technologies that nicely handle the Big Data analytics for Internet of Things are Apache Hadoop and NoSQL. Hadoop is designed for parallelizing analytical work across many servers and is ideal for the massive data volumes you create with IoT devices. NoSQL databases such as Apache HBase are ideal for storing and retrieving IoT data as “time series data.”
Clearly the way forward is to move to cloud be it bare metal, VMs or containers. One aspect of the current public clouds that is slowing this cloud migration is cloud lock-in. Every cloud vendor is trying to make it very difficult to move out once a customer has chosen their cloud. In his session at 17th Cloud Expo, Naveen Nimmu, CEO of Clouber, Inc., will advocate that making the inter-cloud migration as simple as changing airlines would help the entire industry to quickly adopt the cloud without worrying about any lock-in fears. In fact by having standard APIs for IaaS would help PaaS expl...
Organizations already struggle with the simple collection of data resulting from the proliferation of IoT, lacking the right infrastructure to manage it. They can't only rely on the cloud to collect and utilize this data because many applications still require dedicated infrastructure for security, redundancy, performance, etc. In his session at 17th Cloud Expo, Emil Sayegh, CEO of Codero Hosting, will discuss how in order to resolve the inherent issues, companies need to combine dedicated and cloud solutions through hybrid hosting – a sustainable solution for the data required to manage I...
Apps and devices shouldn't stop working when there's limited or no network connectivity. Learn how to bring data stored in a cloud database to the edge of the network (and back again) whenever an Internet connection is available. In his session at 17th Cloud Expo, Bradley Holt, Developer Advocate at IBM Cloud Data Services, will demonstrate techniques for replicating cloud databases with devices in order to build offline-first mobile or Internet of Things (IoT) apps that can provide a better, faster user experience, both offline and online. The focus of this talk will be on IBM Cloudant, Apa...
Mobile messaging has been a popular communication channel for more than 20 years. Finnish engineer Matti Makkonen invented the idea for SMS (Short Message Service) in 1984, making his vision a reality on December 3, 1992 by sending the first message ("Happy Christmas") from a PC to a cell phone. Since then, the technology has evolved immensely, from both a technology standpoint, and in our everyday uses for it. Originally used for person-to-person (P2P) communication, i.e., Sally sends a text message to Betty – mobile messaging now offers tremendous value to businesses for customer and empl...
As more and more data is generated from a variety of connected devices, the need to get insights from this data and predict future behavior and trends is increasingly essential for businesses. Real-time stream processing is needed in a variety of different industries such as Manufacturing, Oil and Gas, Automobile, Finance, Online Retail, Smart Grids, and Healthcare. Azure Stream Analytics is a fully managed distributed stream computation service that provides low latency, scalable processing of streaming data in the cloud with an enterprise grade SLA. It features built-in integration with Azur...
SYS-CON Events announced today that HPM Networks will exhibit at the 17th International Cloud Expo®, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. For 20 years, HPM Networks has been integrating technology solutions that solve complex business challenges. HPM Networks has designed solutions for both SMB and enterprise customers throughout the San Francisco Bay Area.
The enterprise is being consumerized, and the consumer is being enterprised. Moore's Law does not matter anymore, the future belongs to business virtualization powered by invisible service architecture, powered by hyperscale and hyperconvergence, and facilitated by vertical streaming and horizontal scaling and consolidation. Both buyers and sellers want instant results, and from paperwork to paperless to mindless is the ultimate goal for any seamless transaction. The sweetest sweet spot in innovation is automation. The most painful pain point for any business is the mismatch between supplies a...
The broad selection of hardware, the rapid evolution of operating systems and the time-to-market for mobile apps has been so rapid that new challenges for developers and engineers arise every day. Security, testing, hosting, and other metrics have to be considered through the process. In his session at Big Data Expo, Walter Maguire, Chief Field Technologist, HP Big Data Group, at Hewlett-Packard, will discuss the challenges faced by developers and a composite Big Data applications builder, focusing on how to help solve the problems that developers are continuously battling.
As enterprises capture more and more data of all types – structured, semi-structured, and unstructured – data discovery requirements for business intelligence (BI), Big Data, and predictive analytics initiatives grow more complex. A company’s ability to become data-driven and compete on analytics depends on the speed with which it can provision their analytics applications with all relevant information. The task of finding data has traditionally resided with IT, but now organizations increasingly turn towards data source discovery tools to find the right data, in context, for business users, d...
SYS-CON Events announced today that MobiDev, a software development company, will exhibit at the 17th International Cloud Expo®, which will take place November 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. MobiDev is a software development company with representative offices in Atlanta (US), Sheffield (UK) and Würzburg (Germany); and development centers in Ukraine. Since 2009 it has grown from a small group of passionate engineers and business managers to a full-scale mobile software company with over 150 developers, designers, quality assurance engineers, project manage...
Learn how IoT, cloud, social networks and last but not least, humans, can be integrated into a seamless integration of cooperative organisms both cybernetic and biological. This has been enabled by recent advances in IoT device capabilities, messaging frameworks, presence and collaboration services, where devices can share information and make independent and human assisted decisions based upon social status from other entities. In his session at @ThingsExpo, Michael Heydt, founder of Seamless Thingies, will discuss and demonstrate how devices and humans can be integrated from a simple clust...
SYS-CON Events announced today that Cloud Raxak has been named “Media & Session Sponsor” of SYS-CON's 17th Cloud Expo, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. Raxak Protect automates security compliance across private and public clouds. Using the SaaS tool or managed service, developers can deploy cloud apps quickly, cost-effectively, and without error.
Who are you? How do you introduce yourself? Do you use a name, or do you greet a friend by the last four digits of his social security number? Assuming you don’t, why are we content to associate our identity with 10 random digits assigned by our phone company? Identity is an issue that affects everyone, but as individuals we don’t spend a lot of time thinking about it. In his session at @ThingsExpo, Ben Klang, Founder & President of Mojo Lingo, will discuss the impact of technology on identity. Should we federate, or not? How should identity be secured? Who owns the identity? How is identity ...