diff --git a/.gitignore b/.gitignore
new file mode 100644
index 00000000..962bf637
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,22 @@
+# gitignore for WW3
+
+# directories checked out by manage_externals, and other files created
+# by manage_externals
+manage_externals.log
+
+# binary files
+*.nc
+
+# editor files
+*.swp
+*~
+
+# mac files
+.DS_Store
+
+# cime_config
+buildnmlc
+
+# misc
+*.pyc
+*.gz