msbuild XSLT Execute From URL. Courtesy of an ephemeral Casey Smith tweet

xslt.proj

<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003" ToolsVersion="4.0"> 
   <Target Name="Example">
      <ItemGroup>
        <XmlFiles Include="https://gist.githubusercontent.com/caseysmithrc/d6ef2fdffa6c054c6996b0f2fb7dd45d/raw/6ce40c15487d67df6771ff205de5ea8a8c6f29c0/customers.xml" />
      </ItemGroup>
      <PropertyGroup>
        <XslFile>https://gist.githubusercontent.com/caseysmithrc/d6ef2fdffa6c054c6996b0f2fb7dd45d/raw/48abcd2a9575e1e5db25596cbaa02f6066bbe9e2/script.xsl</XslFile>
      </PropertyGroup>
      <XslTransformation
         OutputPaths="output.%(XmlFiles.FileName).html"
         XmlInputPaths="%(XmlFiles.Identity)"
         XslInputPath="$(XslFile)"
         />
   </Target>
</Project>