.NET Core 1.1.1 was released today. Both releases include reliability updates to improve the quality of .NET Core. You can download the .NET Core Runtime releases via our .NET Core Runtimes download page. If you are looking for the .NET Core SDK, to get the latest tools, try the .NET Core SDK download page.
Have a look at the .NET announcement blog post for details and great context around the release. Visual Studio 2017 is also releasing today and you can read about it in their announcement.