Added project URL.
diff --git a/README.txt b/README.txt
index 0c351c3..8b0efa2 100644
--- a/README.txt
+++ b/README.txt
@@ -5,8 +5,8 @@
It can represent integer, real number, string, an ordered sequence of
value, and a collection of name/value pairs.
-JsonCpp is a simple API to manipulate JSON value, handle serialization
-and unserialization to string.
+JsonCpp (http://jsoncpp.sourceforge.net/) is a simple API to manipulate
+JSON value, handle serialization and unserialization to string.
It can also preserve existing comment in unserialization/serialization steps,
making it a convenient format to store user input files.