Announcing Open Source of .NET Core Framework, .NET Core Distribution for Linux/OSX, and Free Visual Studio Community Edition

This week we are holding our Connect() developer event in New York City.  This is an event that is being streamed online for free, and it covers some of the great new capabilities coming with the Visual Studio 2015 and .NET 5 releases.  You can watch the event live as well as on-demand here.

I just finished giving the opening keynote of the event during which I made several big announcements:

Announcing the Open Sourcing of the .NET Core Runtime and Libraries

Over the last several years we have integrated more and more open source technology into our .NET, Visual Studio, and Azure offerings.  We have also begun to open source more of our own code and technology as well.

Earlier this year, at the Build 2014 conference, I announced the creation of the .NET Foundation – which is an independent organization designed to foster the development and collaboration of open source technologies for .NET.  We have now open sourced ASP.NET, EF, Web API, NuGet and the "Roslyn" C# and VB compilers under it. 

It has been great to see the energy and innovation in these technologies since we made the open source announcements. We continue to have dedicated Microsoft teams working on each of them (several of the teams have more developers than ever before).  The open source process is now enabling the teams to collaborate even more with other developers in the community, and every single one of the above projects have now accepted code contributions from developers outside Microsoft.  The combination is enabling an even richer flow of ideas, and even better products.

Open Sourcing the .NET Core Runtime and Libraries

Today I’m excited to announce that we are going even further, and will be open sourcing the .NET Core Runtime.  This will include everything needed to execute .NET code – including the CLR, Just-In-Time Compiler (JIT), Garbage Collector (GC), and core .NET base class libraries.

We are releasing the source under the MIT open source license and are also issuing an explicit patent promise to clarify users patent rights to .NET.  This morning, we published the public repository on GitHub where the project will be hosted:

Today’s source release includes many of the newer core .NET framework libraries (ImmutableCollections, SIMD, XML and MetadataReader).  These libraries are fully open, and are ready to accept contributions.  Over the next several weeks and months we will continue to transfer source (including the Core CLR which is not there right now but in the process of being moved) into the repository and likewise make it open for contributions.

What does this open sourcing mean?

Today’s open source announcement means that developers will have a fully supported, fully open source, fully cross platform .NET stack for creating server and cloud applications – including everything from the C#/VB compilers, to the CLR runtime, to the core .NET base class libraries, to the higher-level .NET Web, Data and API frameworks.

It is an exciting day for .NET, and the new open source process will allow the .NET teams in Microsoft to collaborate even more deeply with other developers around the world.  The result is going to be even better products for everyone.

Announcing .NET Core Framework on Linux and OSX

Last month at a Cloud Event we held in San Francisco, Satya Nadella – our CEO – showed a slide like this one where he talked about how Microsoft loves Linux:


We’ve worked hard with Azure to make it a first-class cloud platform for Linux based applications, and shared how more than 20% of all VMs running on Azure are Linux based.  In fact, we now have 5 different Linux distributions officially supported for use on Azure – with full integration within our management portal and command-line extensibility.

Bringing Core .NET to Linux and OS X

Today I’m excited to announce the .NET side of our Linux support.  In addition to making the .NET server stack open-source, we are also going to release an official distribution of the .NET Core for Linux, as well as an official distribution of .NET Core for the Mac operation system as well.

This will enable you to build .NET server and cloud applications and run them on both Windows Server and Linux.  It is going to enable every developer – regardless of what operating system they use to develop or target – to use .NET. And to do so on a fully open source runtime.

We will be working closely with the Mono community as we complete our Linux port.  The Mono community have done a great job advancing .NET and Linux over the last decade.  Releasing the .NET Core source under an open source license is going to enable us to collaborate together much more closely going forward.  There are many Linux enhancements Mono has built that we would like to use, and likewise there are improvements Mono will be able to benefit from by being able to use the .NET source code.  Today’s set of announcements are a big win for everyone.

Announcing Visual Studio Community Edition

I’m also excited to announce that we are launching a new free edition of Visual Studio today that will empower even more developers to build great apps and solutions.

The new Visual Studio Community 2013 edition is a full-featured IDE.  It supports multiple project types in one solution file in a single IDE, and has all of the productivity features and IDE extensibility capabilities (meaning you can use Xamarin, ReSharper, VsVim, and any other VSIX extension) that developers love in Visual Studio.

It is now available completely free for:

  • Any individual developer working on a commercial or non-commercial project
  • Any developer contributing to an open source project
  • Anyone in an academic research or course setting (e.g. students, teachers, classroom, online course)
  • Any non-enterprise organization with 5 or fewer developers working on a commercial/non-commercial project together

We are making it available for download starting today, and developers can download and start using it immediately.  There is no program you need to join to use it – simply visit, click the download button, and you are good to go. 

It is going to enable even more developers to take advantage of Visual Studio and build even better applications.  We are looking forward to seeing what you build with it.


It has never been a better time to be a software developer.  Software is what enables organizations to succeed in today’s digital environment.  It is what enables businesses to connect better with customers, to deliver amazing new experiences, to drive new revenue streams, and to run operations more efficiently.

Using the cloud, every software developer on the planet can now create and build solutions that can reach millions of users, with no upfront costs, powered by a cloud infrastructure that delivers completely global reach.  The impact an individual developer can now have has never been greater than it is today.

Our goal at Microsoft is to provide developers with the platform and tools that will make them incredibly successful.  It is a mission we have had since the very beginning of the company.  Today’s .NET open source, cross platform, and Visual Studio Community edition announcements will enable the development technology we build to be leveraged by an even wider range of developers.  We are really excited to see some of the new apps and solutions that are built with it.

In addition to the above announcements, we are also announcing and demoing tons of new features and services for the first time at our Connect() event streamed from New York.  You can watch the online presentations here.  Also read Soma’s blog post for a summary of some of the new VS 2015 and .NET 5 capabilities we announced this week.

Hope this helps,


P.S. In addition to blogging, I am also now using Twitter for quick updates and to share links. Follow me at: @scottgu


  • Good news Scott :)
    The obvious question re VS Community Edition is "What does this mean for the Express editions?" - which are limited by project type.

  • That's fantastic news!!

    Another question about VS Community Edition - will there be versions for Linux/OSX?

  • This is super awesome. This is a huge welcome to opensource community.

  • I am weeping with joy over the Visual Studio Community edition. Will it work with TFS online?

  • This is fantastic news! I'm happy to see more and more parts of .NET become truly cross-platform and open source. Also, the Visual Studio Community Edition is highly welcome.

    Again, congratulations on this move!

  • sudo apt-get install visualstudio ??

  • I think I will cry a little

  • This is amazing. I've been following your blog since forever and looking back this announcement was just a dream or a joke back when I started. Congratulations to everyone involved!

  • Awesome job guys!

  • That's a good one :)
    sudo apt-get install visualstudio ??

  • Amazing!! Great job Microsoft

  • I needed to rub my eyes multiple times. Microsoft is waking up and boooooooooosting!

  • Bravo! Such a great news for all of us, finally! Customers uses our applications and they don't care about OS!!!! Right direction!

  • Having trouble wrapping my mind around this. So many questions, but for now let me just say, bravo!

  • Does this include ASP.NET Web Forms ?

  • If Microsoft really wants to make developers "incredibly successful" then it should return to writing documentation URGENTLY, as it used to do a decade ago. Those docs were useful, nowadays' docs are only generated trivialities. I hope these news does not only mean that "use the source, Luke!" whenever you need more info

  • awesome! thanks!

  • Not sure I would be excited about that. I actually suffered a lot from using open source products, like once spent a couple of days trying to get a plugin for eclipse to work and eventually gave up. Same thing when you have a problem with the Linux kernel or one of its configuration files. A nightmare. What I liked most about .NET is that everything is built in and integrated in Visual Studio, fully supported by MS and there is always one authoritative source of information you could go to and find an answer Vs the hacks and solutions discovered by random hobbyists all ovet the World, which rarely work on your side.
    Let’s wait and see how this develops.

  • Amazing!!! Microsoft Reloaded!

  • Nadella is the Gorby of Microsoft... Glasnost, perestroika an then... crashing the system?

  • @Sam Open Source does not mean poorly developed or unsupported. Most of us have suffered pretty bad from commercial software as well.

  • A very good step forward

  • Excellent! Microsoft does love Linux!

  • This has done more for cross platform than anything thus far I think.

  • Great news on Community edition, but I'm gutted as I just shelled out on VS Pro a couple of days ago after months of pondering! As a single developer I could have got VS for free if I'd waited.

  • Now I know I have a reading disorder problem.. because to me it looks like MS is giving free VS Pro and it is being announced by its CEO.
    But just in case you all see what I see - Can someone explain what's the catch? how is this going to be profitable to MS?

  • This is Amazing news :) I'm so happy to see .NET become truly cross platforms and open source. please let me cry

  • @Gil It looks like you'll be able to install VS 2013 CE if only you don't have any other editions of VS.

  • Big deal. Do you dare do the same with VB6?

  • Microsoft is giving away so much free software to developers; the rest is up to us.

    Q: Will VS Community Edition include VS LightSwitch?

    Q: Can VS Community Edition be installed side-by-side so I (we) can evalute w/out destroying VS2013 which is already installed?

    A: I have to concure with homay who remarked about the ongoing need for documentation; development has become so complex many of us self included need to hold hands w/ mentors who developed what we are expected to know how to use.

  • Awesome, Awesome, Awesome. Great news to support Linux and the Visual Studio Community enhancements.
    Thanks, Microsoft.

  • @Andy 2013 Express editions remain available, and for VS2015 we normally don’t talk about SKU plans until we’re closer to release.

    @Mark S, You still need Windows to run Community.

  • Amazing!!! Awesome!!! Great news for software developer(Programmers)..... Thanks Microsoft.

  • I have been anticipating this for quite some time. To those wondering about how this makes MS money, here's how i think the reasoning goes.

    OS platform is becoming irrelevant. Users care less and less, and developers want freedom of choice. Maintaining an OS eco system used to be a matter of prestige, but is basically a monet pit.

    MS is best at apps (think office and sharepoint) and those are profitable.

    Java is used in lots of big enterprise systems, and runs across OS systems. But Java is bleeding, and this move is a direct attack against Oracle.
    MS wants to play Oracle and win in the big enterprise market. And as often before, that battle is won thru the hearts of developers.

    I have developed enterprise systems in both .NET and JEE. I am excited about the new possibilities to come, I like .NET.

    And as always the customers are going to be the winners with more competition.

  • When will be available localized ISOs of Visual Studio 2013 Community Edition?

  • This is not good news.

    I remember times when we had to wait years to see a new IDE, that would need a supercomputer to run and crash twice an hour, and another year to get a service pack to reduce the crashes to once every two hours.
    Today, we get more releases on MVC and EF than we expect, sooner than we expect and when we have any problem, we always have the option to contribute. Many libraries are release out of band and you don't need to wait for the next major .Net or VS release to catch up. And now the core is open sourced.

    This is not good news,
    This is unexpectedly exciting, SUPERB

  • It's hard to find the right words to describe how significant this is.

    This will make the .NET community flourish in ways we could only dream of before.
    This allows for personal growth of the developers who was pushing the boundaries of .NET and Windows. Allowing these to leverage their knowledge of the framework in areas not previously possible.

    Thank you Microsoft!
    I now know where my future lies.

  • Thought I would never see this day. This is big and this is good. Thank you Microsoft for being bold!

  • I think MS initiated self-destruct sequence and the Abort button is returning "An unknown error has occurred" message

  • Better Late Good Work

  • .NET Core cross platform is fantastic news!! Great move!!

  • Hey Scott,

    Next time there's a big announcement like this, do us all a favour, wear a blue shirt.

  • Yay! This is the best news i heard since some time! Microsoft, you listen to our wishes and may God speed you!!


  • Alt+Control+Delete....

  • A very good step forward, Great move!!

  • First of all, a big Thank You to you Scott, and all the folks at Microsoft for the great work that you've been churning out recently! It's truly exciting to be working on the Microsoft stack these days (as you see from the other comments on this thread).

    A couple of questions (and I apologize in advance if these were answered elsewhere already):

    - When you say that we are open-sourcing ASP.NET - are Web Forms included in that category?
    - You mentioned that you are working with Mono community closely - What assurance (if any) can you give us that the Mono project will remain on par with ASP.NET on Windows? If we make design choice to develop an ASP.NET application on a Linux platform, will Microsoft continue to remain committed to the project that we won't be left hanging while ASP.NET on Windows marches on?

  • @glat We don't have plans yet for a localized version of Community.

  • @Clinton Gallagher @virtualCableTV, We did look at making Community an isolated installation similar to Express. The experience we wanted to provide with Community was to provide all of the same functionality as Professional. While we see the value of an isolated installation, bringing together all of the functionality of Professional back onto an Express base represented a significant engineering challenge which introduced risking a degraded experience. In particular we were worried that pursuing that path we would unintentionally break something in use by extensions. By building it off of the existing Professional base we significantly reduced the risk of that. Yes that means it isn’t isolated from other VS installations within the same version, but that is the same experience Pro and higher SKUs have today. As such we felt that was an acceptable trade off. If you have an existing installation of Pro or higher and need to validate an extension or anything else in Community we have made it available as an Azure VM so you can quickly try that out without having to change your primary development machine.

    Regarding LightSwitch, it is not included in Community. It is made available as an extension though so it can be used with Community as described in this post from the LightSwitch team.

  • I think it is a move in the right direction. While .Net is widely used across enterprises, it is not a platform that new startups care about. This along with a lot of free tools, might put Microsoft back in the game.

  • Very good , thank you for share

  • Good , Many libraries are release out of band and you don't need to wait for the next major .

  • I am friso , thank you post

  • Great news. Someone pinch me I may be dreaming. You have no excuse not to be a .Net developer now.

  • Finally Seattle is waking up. What took you guys soo long?

  • Thanks MS...really g8 work..feel like doing party with .Net community . ..:-)

  • I love you Microsoft. Sorry for hating you for 20 years.

  • This is very right way!!!!
    and a next question. Is MS going to buy Xamarin and make it free?

  • Unless Microsoft releases VS CE for Linux and Mac I won't believe they are really fully behind this initiative.

  • Excellent news! The ability to run on Mac or Linux will be outstanding! That should make using tools like xamarin much easier to integrate with VS (since you can then run native for iOS instead of using the existing Xamarin linking feature).

    @moz I don't see them buying Xamarin since they are partners and all their investments in HTML 5... but I've been wrong before...

  • Until there is a usable version of Visual Studio for Linux/OsX that IDE is unusuable for most programmers.

  • Just great! We wanted to make our product available on Linux as well and used Mono for that but with mixed results. MS open sourcing .Net and supporting Linux is just awesome. IMHO the right move to do and it will push .Net a good step forward!!

  • I'm also interested to know whether Visual Studio is planned for release on OSX / Linux.

    Most developers these days seem to have Macs and I'm one of them. However, I have nothing but friction doing .NET development on my Mac either, running Windows in a VM or via Bootcamp. Keyboard and key mappings are the main area of concern and given I'm a .NET developer by trade I'm reluctant to commit to the Mac hardware, beautiful as it is, or OSX. However, if the vision is to have VS running on OSX without the increased friction of running it via a VM, then I guess I might look at the keyboard/mapping issue.

  • I hope Microsoft will let Visual Studio run on MacOS and Linux. That would be very great! :-)

  • Perfectly Perfect. So nice...

  • Its a great news for us. Thanks MS.....

  • How about Phone? wil it run on Android and iPhone?

  • Hee

    Life is good for you at Azure, you gained a few pounds !

  • These are really good news. I am looking forward to officil .NET for linux. :-)

  • Really excited to see .NET core for Linux. It's a smart move with Hadoop primarily on Linux based systems.

  • its a very good hosting site

  • Microsoft should open the VB6 code too !! The VB6 developer community has deserved.

  • I wish MS did this 10... even 5 years ago.. could have changed a lot.

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  • Strange that Microsoft say to abandon Silverlight without given a viable alternative, just by saying that using plugin is not the way to go. There is no alternative at this moment to develop Web application, especially LOB, with ONE technology that has a rich UI experience like “traditional” winform applications. ASP.NET still rely on javascript and css. The same for HTML5/JS/CSS combo and as mentioned by others, both and html5 combo still rely on browser support, especially in rendering controls. Microsoft should NOT introduce new technology and abandon it within a few years like Silverlight where a large developer community has invest in Silverlight. Look at where developers still asking for new features. Why not integrate the Silverlight runtime in the .net runtime i.e. by transforming xaml to html etc.? Developers need ONE technology to develop applications for multiple devices independent of the chosen browser rendering engine….

  • Amazing! We (all the community) hope this become a full implementation and supported product, not just an announcement!

  • this post help me a lot thank you so much

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