.NET Core 3.0 RC 1

.NET Core RC 1 released today. https://github.com/dotnet/core/issues/3380 has been opened for discussion.

[Release Notes](https://github.com/dotnet/core/blob/master/release-notes/3.0/preview/3.0.0-rc1.md)
[Download](https://github.com/dotnet/core/blob/master/release-notes/3.0/preview/3.0.0-rc1-download.md)

**Blog posts**

[.NET Core](https://devblogs.microsoft.com/dotnet/announcing-net-core-3-0-release-candidate-1/)
[ASP.NET Core](https://devblogs.microsoft.com/aspnet/asp-net-core-and-blazor-updates-in-net-core-3-0-release-candidate-1/)

Please report any issues you find with 3.0.0 RC 1, either responding to this issue, creating a new issue or creating a new issue in one of the following repos:

* [aspnet/AspNetCore](https://github.com/aspnet/AspNetCore) - for ASP.NET Core questions
* [aspnet/EntityFrameworkCore](https://github.com/aspnet/EntityFrameworkCore) - for Entity Framework Core questions
* [dotnet/cli](https://github.com/dotnet/cli/issues) - for CLI tools and questions
* [dotnet/corefx](https://github.com/dotnet/corefx/issues) - for API issues and questions
* [dotnet/coreclr](https://github.com/dotnet/coreclr/issues) - for runtime issues
* [dotnet/core-setup](https://github.com/dotnet/core-setup/issues) - for installer issues
* [dotnet/winforms](https://github.com/dotnet/winforms/issues) - for Winforms issues
* [dotnet/wpf](https://github.com/dotnet/wpf/issues) - for WPF issues
* [nuget/home](https://github.com/nuget/home/issues) - for NuGet questions and issues

Start with the linked release notes and download instructions, then read the discussion in dotnet/core#3380. This issue announces .NET Core 3.0 RC 1 and lists repositories for reporting problems, but it names no specific change, file, test, or implementation goal; there is no defined completion condition.

Written by the indexing model from the issue text.