It's a library for parsing JSON, using UnityScript (the programming language used in Unity).
Because JSON is the fat-free XML, and because UnityScript is not JavaScript (even though everybody says it is.).
var dataString = "{\"name\": \"Bob\", \"age\": 22, \"hobbies\": [\"biking\", \"fishing\", \"swimming\"]}";
var parsed = JSONParse.JSONParse(dataString);
print("The person's name is " + parsed["name"] + ", and he is " + parsed["age"].ToString() +
". \n\n His hobbies: " + String.Join(", ", parsed["hobbies"]) + "." );