diff --git a/src/Microsoft.AspNet.Hosting/HostingServicesCollectionExtensions.cs b/src/Microsoft.AspNet.Hosting/HostingServicesCollectionExtensions.cs
index 1c698d3f49..6445c1e4b1 100644
--- a/src/Microsoft.AspNet.Hosting/HostingServicesCollectionExtensions.cs
+++ b/src/Microsoft.AspNet.Hosting/HostingServicesCollectionExtensions.cs
@@ -13,33 +13,30 @@ namespace Microsoft.Framework.DependencyInjection
     public static class HostingServicesExtensions
     {
         // REVIEW: Logging doesn't depend on DI, where should this live?
-        public static IServiceCollection AddLogging(this IServiceCollection services, IConfiguration config = null)
+        public static IServiceCollection AddLogging(this IServiceCollection services)
         {
-            var describe = new ServiceDescriber(config);
-            services.TryAdd(describe.Singleton<ILoggerFactory, LoggerFactory>());
-            services.TryAdd(describe.Singleton(typeof(ILogger<>), typeof(Logger<>)));
+            services.TryAdd(ServiceDescriptor.Singleton<ILoggerFactory, LoggerFactory>());
+            services.TryAdd(ServiceDescriptor.Singleton(typeof(ILogger<>), typeof(Logger<>)));
             return services;
         }
 
         public static IServiceCollection AddHosting(this IServiceCollection services, IConfiguration configuration = null)
         {
-            var describer = new ServiceDescriber(configuration);
+            services.TryAdd(ServiceDescriptor.Transient<IHostingEngine, HostingEngine>());
+            services.TryAdd(ServiceDescriptor.Transient<IServerLoader, ServerLoader>());
 
-            services.TryAdd(describer.Transient<IHostingEngine, HostingEngine>());
-            services.TryAdd(describer.Transient<IServerLoader, ServerLoader>());
+            services.TryAdd(ServiceDescriptor.Transient<IStartupLoader, StartupLoader>());
 
-            services.TryAdd(describer.Transient<IStartupLoader, StartupLoader>());
+            services.TryAdd(ServiceDescriptor.Transient<IApplicationBuilderFactory, ApplicationBuilderFactory>());
+            services.TryAdd(ServiceDescriptor.Transient<IHttpContextFactory, HttpContextFactory>());
 
-            services.TryAdd(describer.Transient<IApplicationBuilderFactory, ApplicationBuilderFactory>());
-            services.TryAdd(describer.Transient<IHttpContextFactory, HttpContextFactory>());
-
-            services.TryAdd(describer.Instance<IApplicationLifetime>(new ApplicationLifetime()));
+            services.TryAdd(ServiceDescriptor.Instance<IApplicationLifetime>(new ApplicationLifetime()));
 
             services.AddTypeActivator(configuration);
             // TODO: Do we expect this to be provide by the runtime eventually?
-            services.AddLogging(configuration);
-            services.TryAdd(describer.Singleton<IHostingEnvironment, HostingEnvironment>());
-            services.TryAdd(describer.Singleton<IHttpContextAccessor, HttpContextAccessor>());
+            services.AddLogging();
+            services.TryAdd(ServiceDescriptor.Singleton<IHostingEnvironment, HostingEnvironment>());
+            services.TryAdd(ServiceDescriptor.Singleton<IHttpContextAccessor, HttpContextAccessor>());
 
             // REVIEW: don't try add because we pull out IEnumerable<IConfigureHostingEnvironment>?
             services.AddInstance<IConfigureHostingEnvironment>(new ConfigureHostingEnvironment(configuration));
diff --git a/src/Microsoft.AspNet.Hosting/Program.cs b/src/Microsoft.AspNet.Hosting/Program.cs
index d050fbf10c..cec49ddb7f 100644
--- a/src/Microsoft.AspNet.Hosting/Program.cs
+++ b/src/Microsoft.AspNet.Hosting/Program.cs
@@ -7,7 +7,6 @@ using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.Framework.ConfigurationModel;
 using Microsoft.Framework.DependencyInjection;
-using Microsoft.Framework.DependencyInjection.Fallback;
 using Microsoft.Framework.Logging;
 using Microsoft.Framework.Runtime;
 
diff --git a/src/Microsoft.AspNet.Hosting/Startup/StartupLoader.cs b/src/Microsoft.AspNet.Hosting/Startup/StartupLoader.cs
index ba6c013f12..bed2a0190d 100644
--- a/src/Microsoft.AspNet.Hosting/Startup/StartupLoader.cs
+++ b/src/Microsoft.AspNet.Hosting/Startup/StartupLoader.cs
@@ -8,7 +8,6 @@ using System.Linq;
 using System.Reflection;
 using Microsoft.AspNet.Builder;
 using Microsoft.Framework.DependencyInjection;
-using Microsoft.Framework.DependencyInjection.Fallback;
 
 namespace Microsoft.AspNet.Hosting.Startup
 {
diff --git a/src/Microsoft.AspNet.RequestContainer/ContainerExtensions.cs b/src/Microsoft.AspNet.RequestContainer/ContainerExtensions.cs
index 06d89995f2..35701937ac 100644
--- a/src/Microsoft.AspNet.RequestContainer/ContainerExtensions.cs
+++ b/src/Microsoft.AspNet.RequestContainer/ContainerExtensions.cs
@@ -6,7 +6,6 @@ using System.Collections.Generic;
 using Microsoft.AspNet.RequestContainer;
 using Microsoft.AspNet.Hosting;
 using Microsoft.Framework.DependencyInjection;
-using Microsoft.Framework.DependencyInjection.Fallback;
 
 namespace Microsoft.AspNet.Builder
 {
@@ -29,7 +28,7 @@ namespace Microsoft.AspNet.Builder
 
         // Note: Manifests are lost after UseServices, services are flattened into ApplicationServices
 
-        public static IApplicationBuilder UseServices(this IApplicationBuilder builder, IEnumerable<IServiceDescriptor> applicationServices)
+        public static IApplicationBuilder UseServices(this IApplicationBuilder builder, IServiceCollection applicationServices)
         {
             return builder.UseServices(services => services.Add(applicationServices));
         }
diff --git a/src/Microsoft.AspNet.TestHost/TestServer.cs b/src/Microsoft.AspNet.TestHost/TestServer.cs
index a626723572..b7350e7c13 100644
--- a/src/Microsoft.AspNet.TestHost/TestServer.cs
+++ b/src/Microsoft.AspNet.TestHost/TestServer.cs
@@ -11,7 +11,6 @@ using Microsoft.AspNet.Hosting.Server;
 using Microsoft.AspNet.Http;
 using Microsoft.Framework.ConfigurationModel;
 using Microsoft.Framework.DependencyInjection;
-using Microsoft.Framework.DependencyInjection.Fallback;
 using Microsoft.Framework.Runtime;
 using Microsoft.Framework.Runtime.Infrastructure;
 
diff --git a/test/Microsoft.AspNet.Hosting.Tests/Fakes/Startup.cs b/test/Microsoft.AspNet.Hosting.Tests/Fakes/Startup.cs
index efcb11537a..8f61d7e4c3 100644
--- a/test/Microsoft.AspNet.Hosting.Tests/Fakes/Startup.cs
+++ b/test/Microsoft.AspNet.Hosting.Tests/Fakes/Startup.cs
@@ -3,7 +3,6 @@
 
 using Microsoft.AspNet.Builder;
 using Microsoft.Framework.DependencyInjection;
-using Microsoft.Framework.DependencyInjection.Fallback;
 using Microsoft.Framework.OptionsModel;
 using System;
 
diff --git a/test/Microsoft.AspNet.Hosting.Tests/HostingEngineTests.cs b/test/Microsoft.AspNet.Hosting.Tests/HostingEngineTests.cs
index 99be47cbf7..d66e77a396 100644
--- a/test/Microsoft.AspNet.Hosting.Tests/HostingEngineTests.cs
+++ b/test/Microsoft.AspNet.Hosting.Tests/HostingEngineTests.cs
@@ -10,7 +10,6 @@ using Microsoft.AspNet.FeatureModel;
 using Microsoft.AspNet.Hosting.Server;
 using Microsoft.Framework.ConfigurationModel;
 using Microsoft.Framework.DependencyInjection;
-using Microsoft.Framework.DependencyInjection.Fallback;
 using Xunit;
 
 namespace Microsoft.AspNet.Hosting
diff --git a/test/Microsoft.AspNet.Hosting.Tests/HostingServicesFacts.cs b/test/Microsoft.AspNet.Hosting.Tests/HostingServicesFacts.cs
index 5e6e733da8..1ccae6b90c 100644
--- a/test/Microsoft.AspNet.Hosting.Tests/HostingServicesFacts.cs
+++ b/test/Microsoft.AspNet.Hosting.Tests/HostingServicesFacts.cs
@@ -5,7 +5,6 @@ using System;
 using System.Collections.Generic;
 using Microsoft.AspNet.Hosting.Fakes;
 using Microsoft.Framework.DependencyInjection;
-using Microsoft.Framework.DependencyInjection.Fallback;
 using Microsoft.Framework.Runtime;
 using Xunit;
 
diff --git a/test/Microsoft.AspNet.Hosting.Tests/StartupManagerTests.cs b/test/Microsoft.AspNet.Hosting.Tests/StartupManagerTests.cs
index db19ddc403..cefc9877e7 100644
--- a/test/Microsoft.AspNet.Hosting.Tests/StartupManagerTests.cs
+++ b/test/Microsoft.AspNet.Hosting.Tests/StartupManagerTests.cs
@@ -7,7 +7,6 @@ using Microsoft.AspNet.Builder;
 using Microsoft.AspNet.Hosting.Fakes;
 using Microsoft.AspNet.Hosting.Startup;
 using Microsoft.Framework.DependencyInjection;
-using Microsoft.Framework.DependencyInjection.Fallback;
 using Microsoft.Framework.OptionsModel;
 using Xunit;
 
diff --git a/test/Microsoft.AspNet.Hosting.Tests/UseRequestServicesFacts.cs b/test/Microsoft.AspNet.Hosting.Tests/UseRequestServicesFacts.cs
index 10859e7323..bc557d59e7 100644
--- a/test/Microsoft.AspNet.Hosting.Tests/UseRequestServicesFacts.cs
+++ b/test/Microsoft.AspNet.Hosting.Tests/UseRequestServicesFacts.cs
@@ -6,7 +6,6 @@ using Microsoft.AspNet.Builder;
 using Microsoft.AspNet.Http.Core;
 using Microsoft.AspNet.RequestContainer;
 using Microsoft.Framework.DependencyInjection;
-using Microsoft.Framework.DependencyInjection.Fallback;
 using Microsoft.Framework.Logging;
 using Xunit;
 
diff --git a/test/Microsoft.AspNet.TestHost.Tests/TestClientTests.cs b/test/Microsoft.AspNet.TestHost.Tests/TestClientTests.cs
index 467aca2005..b392bac6ad 100644
--- a/test/Microsoft.AspNet.TestHost.Tests/TestClientTests.cs
+++ b/test/Microsoft.AspNet.TestHost.Tests/TestClientTests.cs
@@ -8,7 +8,7 @@ using System.Threading.Tasks;
 using Microsoft.AspNet.Builder;
 using Microsoft.AspNet.Hosting;
 using Microsoft.AspNet.Http;
-using Microsoft.Framework.DependencyInjection.Fallback;
+using Microsoft.Framework.DependencyInjection;
 using Xunit;
 
 namespace Microsoft.AspNet.TestHost
diff --git a/test/Microsoft.AspNet.TestHost.Tests/TestServerTests.cs b/test/Microsoft.AspNet.TestHost.Tests/TestServerTests.cs
index 9838e1d0b3..c9ef3bdf96 100644
--- a/test/Microsoft.AspNet.TestHost.Tests/TestServerTests.cs
+++ b/test/Microsoft.AspNet.TestHost.Tests/TestServerTests.cs
@@ -10,7 +10,6 @@ using Microsoft.AspNet.Builder;
 using Microsoft.AspNet.Hosting;
 using Microsoft.AspNet.Http;
 using Microsoft.Framework.DependencyInjection;
-using Microsoft.Framework.DependencyInjection.Fallback;
 using Xunit;
 
 namespace Microsoft.AspNet.TestHost