diff --git a/ArcFormats/ArcFormats.csproj b/ArcFormats/ArcFormats.csproj
index 6eb91a32..feb66610 100644
--- a/ArcFormats/ArcFormats.csproj
+++ b/ArcFormats/ArcFormats.csproj
@@ -170,6 +170,7 @@
     <Compile Include="Maika\ArcBK.cs" />
     <Compile Include="Maika\ArcMIK01.cs" />
     <Compile Include="Maika\AudioWV5.cs" />
+    <Compile Include="Noesis\ArcIGA.cs" />
     <Compile Include="NonColor\ArcMinato.cs" />
     <Compile Include="Misc\ArcBIN.cs" />
     <Compile Include="Nekopunch\ImagePBM.cs" />
diff --git a/ArcFormats/Noesis/ArcIGA.cs b/ArcFormats/Noesis/ArcIGA.cs
new file mode 100644
index 00000000..d478052e
--- /dev/null
+++ b/ArcFormats/Noesis/ArcIGA.cs
@@ -0,0 +1,111 @@
+//! \file       ArcIGA.cs
+//! \date       2018 May 04
+//! \brief      Noesis resource archive.
+//
+// Copyright (C) 2018 by morkt
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to
+// deal in the Software without restriction, including without limitation the
+// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+// sell copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+// IN THE SOFTWARE.
+//
+
+using System.Collections.Generic;
+using System.ComponentModel.Composition;
+using System.IO;
+
+namespace GameRes.Formats.Noesis
+{
+    internal class IgaEntry : Entry
+    {
+        public uint NameOffset;
+    }
+
+    [Export(typeof(ArchiveFormat))]
+    public class IgaOpener : ArchiveFormat
+    {
+        public override string         Tag { get { return "IGA"; } }
+        public override string Description { get { return "Noesis resource archive"; } }
+        public override uint     Signature { get { return 0x30414749; } } // 'IGA0'
+        public override bool  IsHierarchic { get { return false; } }
+        public override bool      CanWrite { get { return false; } }
+
+        public override ArcFile TryOpen (ArcView file)
+        {
+            using (var input = file.CreateStream())
+            {
+                input.Position = 0x10;
+                uint index_length = ReadPackedUInt (input);
+                var dir = new List<Entry>();
+                long end_pos = input.Position + index_length;
+                while (input.Position < end_pos)
+                {
+                    var entry = new IgaEntry();
+                    entry.NameOffset = ReadPackedUInt (input);
+                    entry.Offset     = ReadPackedUInt (input);
+                    entry.Size       = ReadPackedUInt (input);
+                    dir.Add (entry);
+                }
+                uint names_length = ReadPackedUInt (input);
+                long data_offset = input.Position + names_length;
+                for (int i = 0; i < dir.Count; ++i)
+                {
+                    var entry = dir[i] as IgaEntry;
+                    uint name_length;
+                    if (i + 1 < dir.Count)
+                        name_length = (dir[i+1] as IgaEntry).NameOffset - entry.NameOffset;
+                    else
+                        name_length = names_length - entry.NameOffset;
+                    entry.Name = ReadPackedString (input, name_length);
+                    entry.Type = FormatCatalog.Instance.GetTypeFromName (entry.Name);
+                    entry.Offset += data_offset;
+                    if (!entry.CheckPlacement (file.MaxOffset))
+                        return null;
+                }
+                return new ArcFile (file, this, dir);
+            }
+        }
+
+        public override Stream OpenEntry (ArcFile arc, Entry entry)
+        {
+            var data = arc.File.View.ReadBytes (entry.Offset, entry.Size);
+            int key = entry.Name.HasExtension (".s") ? 0xFF : 0;
+            for (int i = 0; i < data.Length; ++i)
+                data[i] ^= (byte)((i + 2) ^ key);
+            return new BinMemoryStream (data, entry.Name);
+        }
+
+        static uint ReadPackedUInt (IBinaryStream input)
+        {
+            uint val = 0;
+            while ((val & 1) == 0)
+            {
+                val = val << 7 | input.ReadUInt8();
+            }
+            return val >> 1;
+        }
+
+        static string ReadPackedString (IBinaryStream input, uint length)
+        {
+            var bytes = new byte[length];
+            for (uint i = 0; i < length; ++i)
+            {
+                bytes[i] = (byte)ReadPackedUInt (input);
+            }
+            return Encodings.cp932.GetString (bytes);
+        }
+    }
+}