Well, it is? for i want to add a libary to it but it is on the web.

Yes. Go to this page: http://textadventures.co.uk/create
Find the game you want and click the 'Download' button.

Just keep in mind that you can't upload it back to the online version for editing.

i tried but it didn't work for some reason.
It won't open the file.

Could you post a link? Which library do you want to download?