Rewrites files server based off user-agent using IIS rewrite module.
This module will rewrite urls to the es5 folder if an es5 browser is detected or es6 if a es6 browser is detected.
MORE DOCS ON HOW TO REGISTER AND SETUP THE PROVIDER
Sample rewrite rules for web.config
<rule name="Polymer2ExtensionLessUrls" patternSyntax="Wildcard" stopProcessing="true">
<match url="*.*" negate="true" ></match>
<conditions>
<add input="{REQUEST_FILENAME}" matchType="IsDirectory" negate="true" ></add>
<add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" ></add>
</conditions>
<action type="Rewrite" url="{Polymer2Rewriter:INDEX,|{HTTP_USER_AGENT},|{QUERY_STRING},|{URL}}" ></action>
</rule>
<rule name="Polymer2Es5Es6Rewrite" stopProcessing="true">
<match url="(.*)" ></match>
<action type="Rewrite" url="{Polymer2Rewriter:FILE,|{HTTP_USER_AGENT},|{QUERY_STRING},|{URL}}" ></action>
</rule>
</rules>