diff --git a/SabreTools.Library/External/SupportedFiles/ZipFile.cs b/SabreTools.Library/External/SupportedFiles/ZipFile.cs
index 0bb568df..a674a8ce 100644
--- a/SabreTools.Library/External/SupportedFiles/ZipFile.cs
+++ b/SabreTools.Library/External/SupportedFiles/ZipFile.cs
@@ -17,7 +17,6 @@ using MemoryStream = System.IO.MemoryStream;
 using PathTooLongException = System.IO.PathTooLongException;
 using Stream = System.IO.Stream;
 #endif
-using OCRC;
 
 namespace ROMVault2.SupportedFiles.Zip
 {
diff --git a/SabreTools.Library/External/SupportedFiles/ZipFileEntry.cs b/SabreTools.Library/External/SupportedFiles/ZipFileEntry.cs
index 56a06e2e..4ffb3486 100644
--- a/SabreTools.Library/External/SupportedFiles/ZipFileEntry.cs
+++ b/SabreTools.Library/External/SupportedFiles/ZipFileEntry.cs
@@ -8,7 +8,6 @@ using SabreTools.Library.Data;
 using SabreTools.Library.Tools;
 
 using Ionic.Zlib;
-using OCRC;
 
 namespace ROMVault2.SupportedFiles.Zip
 {
diff --git a/SabreTools.Library/External/Traverse.cs b/SabreTools.Library/External/Traverse.cs
deleted file mode 100644
index 0f3c145b..00000000
--- a/SabreTools.Library/External/Traverse.cs
+++ /dev/null
@@ -1,69 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Threading.Tasks;
-
-#if MONO
-using System.IO;
-#else
-using Alphaleonis.Win32.Filesystem;
-
-using IOException = System.IO.IOException;
-using SearchOption = System.IO.SearchOption;
-#endif
-using SabreTools.Library.Data;
-
-namespace SabreTools.Library.External
-{
-	public class Traverse
-	{
-		/// Original version: Microsoft (example code), updated by edc
-		public void TraverseTreeParallelForEach(string root, Action<FileInfo> action)
-		{
-			List<string> dirs = new List<string>();
-
-			if (!Directory.Exists(root))
-			{
-				throw new ArgumentException();
-			}
-
-			dirs.Add(root);
-
-			List<string> subdirs = new List<string>();
-
-			while (dirs.Count > 0 || subdirs.Count > 0)
-			{
-				foreach (string dir in subdirs)
-				{
-					dirs.Add(dir);
-				}
-				subdirs.Clear();
-
-				foreach (string currentDir in dirs)
-				{
-					string[] subDirs = Directory.GetDirectories(currentDir);
-
-					lock (subdirs)
-					{
-						foreach (string str in subDirs)
-						{
-							subdirs.Add(str);
-						}
-					}
-
-					var dir = new DirectoryInfo(currentDir);
-					try
-					{
-						FileInfo[] files = dir.GetFiles("*.*", SearchOption.TopDirectoryOnly);
-						Parallel.ForEach(files, Globals.ParallelOptions, info =>
-						{
-							action(info);
-						});
-					}
-					catch { }
-				}
-
-				dirs.Clear();
-			}
-		}
-	}
-}
diff --git a/SabreTools.Library/External/CoreRarArchive.cs b/SabreTools.Library/FileTypes/CoreRarArchive.cs
similarity index 98%
rename from SabreTools.Library/External/CoreRarArchive.cs
rename to SabreTools.Library/FileTypes/CoreRarArchive.cs
index 301f1321..34c31118 100644
--- a/SabreTools.Library/External/CoreRarArchive.cs
+++ b/SabreTools.Library/FileTypes/CoreRarArchive.cs
@@ -5,7 +5,7 @@ using SabreTools.Library.Data;
 /// <summary>
 /// http://www.rarlab.com/technote.htm#srvheaders
 /// </summary>
-namespace SabreTools.Library.Tools
+namespace SabreTools.Library.FileTypes
 {
 	public class CoreRarArchive
 	{
diff --git a/SabreTools.Library/SabreTools.Library.csproj b/SabreTools.Library/SabreTools.Library.csproj
index 86564640..9ea8b862 100644
--- a/SabreTools.Library/SabreTools.Library.csproj
+++ b/SabreTools.Library/SabreTools.Library.csproj
@@ -131,11 +131,10 @@
     <Compile Include="DatFiles\SeparatedValue.cs" />
     <Compile Include="DatFiles\SoftwareList.cs" />
     <Compile Include="FileTypes\CHDFile.cs" />
-    <Compile Include="External\CoreRarArchive.cs" />
+    <Compile Include="FileTypes\CoreRarArchive.cs" />
     <Compile Include="External\NaturalSort\NaturalComparer.cs" />
     <Compile Include="External\NaturalSort\NaturalReversedComparer.cs" />
-    <Compile Include="External\OptimizedCRC.cs" />
-    <Compile Include="External\Traverse.cs" />
+    <Compile Include="Tools\OptimizedCRC.cs" />
     <Compile Include="External\xxHash\xxHash.cs" />
     <Compile Include="External\Zlib\CRC32.cs" />
     <Compile Include="External\Zlib\Deflate.cs" />
diff --git a/SabreTools.Library/External/OptimizedCRC.cs b/SabreTools.Library/Tools/OptimizedCRC.cs
similarity index 99%
rename from SabreTools.Library/External/OptimizedCRC.cs
rename to SabreTools.Library/Tools/OptimizedCRC.cs
index 62fe1ece..b3df1ef1 100644
--- a/SabreTools.Library/External/OptimizedCRC.cs
+++ b/SabreTools.Library/Tools/OptimizedCRC.cs
@@ -23,9 +23,8 @@
 */
 
 using System;
-using System.IO;
 
-namespace OCRC
+namespace SabreTools.Library.Tools
 {
 	public class OptimizedCRC : IDisposable
 	{
diff --git a/SabreTools.Library/Tools/Utilities.cs b/SabreTools.Library/Tools/Utilities.cs
index f8a56851..68617b83 100644
--- a/SabreTools.Library/Tools/Utilities.cs
+++ b/SabreTools.Library/Tools/Utilities.cs
@@ -35,7 +35,6 @@ using Stream = System.IO.Stream;
 using StreamReader = System.IO.StreamReader;
 #endif
 using NaturalSort;
-using OCRC;
 using SharpCompress.Common;
 
 namespace SabreTools.Library.Tools