The Developer Ecosystem in 2020: Key Trends for C#

Rachel Appel

At JetBrains, we make tools for developers, so we keep up with the latest trends and changes in the software development industry. We build many IDEs based on multi-platform software product lines for various programming languages.

Our Developer Ecosystem Survey, which JetBrains runs yearly, aims to reveal the current ambience of the developer world. Today we are happy to share with you the results of the 2020 edition of this survey, focusing on C#.


Top C# Discoveries

C# developers largely keep up to date
, with roughly half of all C# developers working in version 8. While many still support legacy C# codebases, the results show that all previous versions of C# have fewer developers this year than they did last year. C# 7 is down to 48% from 63%, and C# 6 is down to 27% from 39%, both showing significant drops in usage.

C# versions

The most popular C# runtime is .NET Framework! While C# developers keep their language skills up to date, many haven’t migrated to .NET Core, yet. However, .NET Core is gaining popularity as 57% of C# developers use it regularly. We suspect that .NET Core will become more popular next year than .NET.

Runtimes used

Web developers who create ASP.NET web apps have been the largest group of developers in the .NET development world for some time now. So it’s no surprise that ASP.NET Core is the most popular framework (55%), and ASP.NET MVC is still quite popular (42%). However, ASP.NET MVC has become less popular over time. On the desktop side, the majority of developers use Windows Forms (31%), followed closely by WPF (26%). Framework usage is rather similar to that of last year’s survey, with nearly identical percentages of usage for each framework.

Frameworks used

There’s no surprise in the answers to this question! Overwhelmingly, C# developers run Windows – 92% to be exact. Sure, Microsoft has gone cross-platform in recent years, however, enterprise development hasn’t necessarily followed suit, so Windows remains the platform of choice in this realm.

Windows OS is popular

Visual Studio is still the IDE used by most people, but we can see it’s being challenged by Rider and VS Code. Visual Studio for Mac is at 2%, and with 14% of people using macOS, it seems that Visual Studio is not the default choice for Mac developers.

IDEs and editors

As far as unit testing goes, MS Test took a fairly large drop since last year, from 36% to 20%. NUnit and XUnit are similar in popularity this year, with 37% of developers using NUnit and 32% using XUnit. Both frameworks have gained a following in the past year of a few percentage points each. This year, 16% of developers didn’t respond to the question, implying that they don’t test at all.

Unit testing

The raw data (obviously, anonymized) will be published later, so you can investigate and analyze it deeper on your own. If you have any comments or thoughts on the C# or .NET facts presented here, share them in the comments below!

Your .NET Team
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20 Responses to The Developer Ecosystem in 2020: Key Trends for C#

  1. svick says:

    June 16, 2020

    Please, don’t talk about the .Net Framework as just “.Net”. Considering the upcoming .Net 5, I think it’s very confusing to talk this way.

    • Matthias Koch says:

      June 17, 2020

      Agree, fixed already. Thank you! 🙂

  2. Saravanan Sivabal says:

    June 17, 2020

    Good to know!. Other than re-usable libraries, I don’t know where the core is in place?

  3. Joan Comas says:

    June 17, 2020

    .NET 5 is launching in November and its supposed to unify NET Framework and NET Core.

    Why do you still predicting that in 2021 Core will be more used than Framework?

    • Rachel Appel says:

      June 17, 2020


      The data shows a constant upswing with .NET Core, and by the time this survey rolls around again .NET 5 will just barely be out. Since there’s often a lag in release to popular usage/uptake, more people at that point should be on .NET Core for a short time until it’s all unified and the new version becomes the popular one – probably for most of our next survey cycle. After that, the question could very well be unnecessary in future surveys, or it might ask something different but more relevant, such as “Are you using .NET 5 or previous version?” without reference to .NET Core.

      Also of note: The predictions here could play out differently than the data suggests or as envisioned. They are not meant to be taken as absolute statements of future events.

      • Dan Neely says:

        June 23, 2020

        Next years survey should still group .net 5 with .net core for comparison with .net framework. 5 may officially be the designated successor to both .net framework and .net core; but in terms of compatibility it’ll still be a simple in place upgrade from the previous version of .netcore and one that will potentially require major changes coming from 4.x if you’ve got any libraries not compatible with core and a big noisy diff where you do a mass namespace swapout to replace equivalent framework and core classes even if everything else just works.

        • Rachel Appel says:

          June 23, 2020

          Thanks Dan.

          I will send your comment to the survey team as I don’t participate in making the survey, I only distill the results.

  4. Rafael Andrade says:

    June 17, 2020

    The link to see “view the state of developer ecosystem 2020 report” is redirecting to 2019 🙁

  5. Kmldf says:

    June 17, 2020

    So every developer knows that stack overflow survey is a joke but somehow copywriters decide to make predictions out of it.

    • Sasa Krsmanovic says:

      June 18, 2020

      This seems a JetBrains survey, not a SO survey though.

      • Rachel Appel says:

        June 18, 2020

        Yes. It is a JetBrains survey, not a Stackoverflow survey.

  6. Jerrie Pelser says:

    June 17, 2020

    I am surprised at the popularity of NUnit as I cannot remember the last time I came across a project that used it. I would have thought XUnit was the most popular by far.

    • Jerome avelino says:

      June 18, 2020

      I use nunit over xunit because its hard to disable its parallel execution. Which i need when i test inmemory db

      • Rob G says:

        June 23, 2020

        No you don’t – you just to generate unique DB names for each test. A GUID generated as part of the name does the trick nicely.

    • Rachel Appel says:

      June 18, 2020

      Jerrie – I also expected XUnit to be more popular.

  7. Kim Jonas says:

    June 22, 2020

    Good Info to know Rachel but when compared with Stackoverflow trends it’s completely different.

    • Rachel Appel says:

      June 22, 2020

      Absolutely! We don’t have the same exact audience, nor do we ask the same exact questions in the same way.

  8. Thorn says:

    June 22, 2020

    Keep in mind that Core got its people just thanks to MS “massive convincing” (read ADVERT). But people can (and will!) easy return, once they find that WinForms/WPF simply DO NOT EXIST for Linux! As well as some other technologies, which MS simply cannot port.

    It’s not saying “multiplatform” hysteria slows down as soon as people realize that it’s just pipe dream. Waste 10x more resources just to see linupsoid face “Ah, it’s .NET app… OK!”. SERIOUS?! I respect myself not to waste my time on MS “inventions”.

    .NET had to be done properly 18 YEARS AGO! Now it’s simply late to “fix the system”. Use to it.

  9. Thorn says:

    June 22, 2020

    One more interesting stuff is the way people asked – it’s tricky psychology and result completely depends from HOW you ask!

    Question: do you use .NET Core?
    Answer: yep, sure! I already made 2 projects (each 10 LOC) to convert cm to inches. (WHOA!) But at work I completely sit on FW.
    Conclusion: Hey, Core is popular! 248%!

    Question: Are you ready to give up all your .NET FW work and completely move on Core stack?
    Answer: Umm… omm… NO!
    Conclusion: Core has below 1% usage and absolutely NOT READY for production.

    Two different results, having the same society! Magic! :))


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