It's a 'brave new world' or 'hell has frozen over' (depending on your point-of-view). Microsoft is the top contributor on GitHub, they have opened-sourced their entire .NET platform and gone cross-platform! In this talk we will look at what the new 'Open-Source' Microsoft actually looks like, what they've done, how they're doing it and what it all means. From new features to compiler design meetings, from TechEmpower benchmarks to increased community contributions, we will examine it all!

1. Microsoft and Open Source
a ‘brave new world’
www.mattwarren.org
@matthewwarren

2. Microsoft and Open Source
a ‘brave new world’
What happened when Microsoft
Open-Sourced EVERYTHING*
* Well, not quite everything, but pretty much all of the .NET Framework

3. Before

5. Microsoft takes .NET
Open Source

8. Licensing

9. Licensing

10. https://blogs.msdn.microsoft.com/bethmassi/2015/02/25/understanding-net-2015/

11. https://blogs.msdn.microsoft.com/bethmassi/2015/02/25/understanding-net-2015/

12. CoreCLR & CoreFX
CoreCLR – Runtime or Virtual Machine
• Garbage collector
• JIT compiler
• Base .NET data types
• Many low-level classes
CoreFX - Core Libraries
• System.Collections
• System.IO
• System.Xml

13. CoreFX Labs
Future work
Span<T> (a.k.a Slices)
High-performance text processing

14. Cmd-Line Tooling (CLI)
λ dotnet new
Created new C# project in
C:usersmattdotnet.
λ dotnet restore
log : Restoring packages for
C:usersmattdotnetproject.json...
log : Writing lock file to disk. Path:
C:usersmattdotnetproject.lock.json
log : Restore completed in 23512ms.
λ dotnet build
Compiling dotnet for .NETCoreApp,Version=v1.1
Compilation succeeded.
0 Warning(s)
0 Error(s)
Time elapsed 00:00:01.9025293
λ dotnet run
Hello World!

15. Roslyn (C# Compiler)
C# compiler, written in C#
Can be consumed by 3rd parties
• Syntax highlighting
• Analysers
• Tooling
Language Design Discussions

16. TypeScript

17. VS Code

18. Kestrel Web Server

19. During

20. The First PR

21. Comedy PRs

22. Good
• Organisation and Process
• Never let PR’s rot
• Provide infrastructure
• Allow the community ‘in’
• ‘Getting started’ guides

23. Bad
• Some decisions made behind ‘closed doors’ (e.g. ‘project.json’)
• Microsoft still the ‘gate-keepers’
• Issues slipping through the gaps

24. After

25. Do .NET developers care?

26. Do .NET developers care?
Did going open-source make any difference?

27. The organization with the largest
number of contributors to open-
source projects over the past year on
GitHub is, surprisingly, Microsoft,
GitHub announced today.
https://octoverse.github.com/

29. Are Microsoft telling the truth?

30. Are Microsoft telling the truth?
There’s only one way to find out!!

31. async Task<SearchIssuesResult> RunQuery(GitHubClientInfo clientInfo,
string query, int pageSize, int pageNumber)
{
var issue = new SearchIssuesRequest(query);
issue.Repos.Add(clientInfo.Organisation, clientInfo.Repository);
issue.SortField = IssueSearchSort.Created;
issue.Order = SortDirection.Ascending;
issue.PerPage = pageSize;
issue.Page = pageNumber;
var result = await clientInfo.Client.Search.SearchIssues(issue);
return result;
}
C#

32. Open Source .NET – 2 years later
http://mattwarren.org/2016/11/23/open-source-net-2-years-later/

33. Do .NET developers care?
• Sustained contributions
• Not just an initial bump
• Opening issues and creating pull-requests
• Bug fixes, entire features, future ideas
• Across the entire stack
• Runtime, Class libraries, Compiler, JIT and even GC

34. Questions?
www.mattwarren.org
@matthewwarren