Storing a language array

Hello, I am working on an international site, which at the moment stores values in an XML file. At the moment it has about 1000 lines. Then for each page load it scans through the entire file, making an array, which can be accessed anytime on the page. I could just do a XML file for each page, but a lot of pages use the same language so would be easier not to. This is stupid, and I was wondering what the best method is? Should it be put in a session? I would like a way, if needed, to quickly alter the text so everyone sees the new text, but mostly it won't alter. If it is stored in a session, will that not mean there is a copy for each user on the website? Is there an alternative way to store the values? Any help would be great. Thanks, Steve