Assembly: EPiServer (in EPiServer.dll) Version: 5.2.375.236
public class LanguageManager : IDisposable
You should never need to create your own instance of this class, always use the Instance instance. The simple reason is that this object is very heavyweight and creating a new instance on every request will consume more memory and CPU than you want.
LanguageManager will start a file monitor over the specified directory and then merge all XML files found.