diff --git a/Casks/firestormos.rb b/Casks/firestormos.rb
new file mode 100644
index 0000000000..565cf456e5
--- /dev/null
+++ b/Casks/firestormos.rb
@@ -0,0 +1,18 @@
+cask :v1 => 'firestormos' do
+  version '4.6.9.42974'
+  sha256 '423c7f6f0d262153fa655fd8a39b6d56c22744c57dfc2d7972bf4bf94d612459'
+
+  url "http://downloads.firestormviewer.org/mac/Phoenix-FirestormOS-Releasex64-#{version.gsub('.','-')}.dmg"
+  name 'Phoenix Firestorm viewer for Second Life'
+  homepage 'http://www.firestormviewer.org'
+  license :oss
+
+  app 'FirestormOS-Releasex64.app'
+
+  caveats <<-EOS.undent
+    This version does not contain Havok engine (does not matter if you're not a content creator).
+    Most problems that crop up during updates can be resolved or fixed by performing a clean install:
+
+      http://wiki.phoenixviewer.com/doku.php?id=fs_clean_reinstall for instructions.
+  EOS
+end