gistfile1.txt

You can use Visual Studio 2015 to compile to Compact Framework 3.5 by following the instructions below:

- Install the '.NET Compact Framework 3.5 Redistributable';
- Copy files from '*C:\Program Files (x86)\Microsoft.NET\SDK\CompactFramework\v3.5\WindowsCE*';
- Paste the files at '*C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\\.NETFramework\v3.5\Profile\CompactFramework*' directory;
- Create a directory named '*RedistList*';
- Create a file named '*FrameworkList.xml*' at '*RedistList*' directory;
- Set the follwing content to the file created:

        <?xml version="1.0" encoding="utf-8"?>
        <FileList  Redist="Net35-CF" Name=".NET Compact Framework 3.5">
        </FileList>

Now you can create a **.NET Core Class Library** project on Visual Studio 2015 and target '*net35-cf*' framework.

To use async/await you can use the *System.Threading.Tasks.WindowsCE* package.

An example project can be found at: https://github.com/WindowsCE/System.Collections.Concurrent/tree/08669ca5b45cc5c74c8c225a633828f9e26b5276

Disclaimer: I'm the author of the package and the project above.