C#

var LanguageDoc = new XmlDocument();
LanguageDoc.Load(fPath);

XmlNode root = LanguageDoc.DocumentElement;
XmlNode main = root.SelectSingleNode("/language/main");
XmlNode about = main.SelectSingleNode("aboutlink");
Console.WriteLine("About: {0}", about == null ? "NULL" : about.InnerText);
XmlNode registration = main.SelectSingleNode("registrationlink");
Console.WriteLine("Registration: {0}", registration == null ? "NULL" : registration.InnerText);
XmlNode login = main.SelectSingleNode("loginlink");
Console.WriteLine("Login: {0}", login == null ? "NULL" : login.InnerText);

/*
Output:

About: About
Registration: Registration
Login: Enter
*/

XML Declaration - MSDN[^]

The XML declaration is not required, however, if used it must be the first line in the document and no other content or white space can precede it.

<?xml version="1.0" encoding="utf-8" ?>