Create a web service (App Pool, Web Site, Web Application in IIS), Compiles the code to a separate assembly, Gives permissions to the app pool identity to the web service folder.

WebService.linq

<Query Kind="Program">
  <Reference>&lt;RuntimeDirectory&gt;\Microsoft.CSharp.dll</Reference>
  <Reference>&lt;RuntimeDirectory&gt;\System.Runtime.InteropServices.dll</Reference>
  <Reference>&lt;RuntimeDirectory&gt;\System.Runtime.InteropServices.WindowsRuntime.dll</Reference>
  <Reference>&lt;RuntimeDirectory&gt;\System.Runtime.Serialization.dll</Reference>
  <Reference>&lt;RuntimeDirectory&gt;\System.ServiceModel.dll</Reference>
  <NuGetReference>Microsoft.Web.Administration</NuGetReference>
  <NuGetReference>NUnitLite</NuGetReference>
  <NuGetReference>CodingArchitect.Utilities</NuGetReference>
  <Namespace>Microsoft.CSharp</Namespace>
  <Namespace>Microsoft.CSharp.RuntimeBinder</Namespace>
  <Namespace>Microsoft.Web.Administration</Namespace>
  <Namespace>NUnit.Framework</Namespace>
  <Namespace>NUnitLite</Namespace>
  <Namespace>System.CodeDom.Compiler</Namespace>
  <Namespace>System.Runtime.InteropServices</Namespace>
</Query>

void Main()
{	
	var queryDirectory = Path.GetDirectoryName(Util.CurrentQueryPath);
	Environment.CurrentDirectory = queryDirectory;
	
	var companyName = "CodingArchitect";	
	var serviceWebsitetName = "WebServiceUsingLinqpad";
	var port = "9898";
	var webServiceTypeName = "GreeterService";
	
	CodingArchitect.Utilities.Linqpad.Util.SetupWebService(companyName, serviceWebsitetName, port, webServiceTypeName, queryDirectory, Util.CurrentQueryPath);
	
}
// Define other methods and classes here
} 

#region Service Classes
namespace CodingArchitect.Spikes.WebServiceUsingLinqpad
{
	using System.ServiceModel;
	public class GreeterService : IGreeterService
	{
		public string Greet()
		{
			// Simulate I/O
			Thread.Sleep(1000);
			return "Hello World from Web Service";
		}
	}
	
	[ServiceContract]
	public interface IGreeterService
	{
		[OperationContract]
		string Greet();
	}
}
#endregion
class EOF {