How do you create files with JavaScript? [duplicate]

Question

Possible Duplicate:
Force download of ‘data:text/plain’ URL
Create a downloadable link from a vriable in javascript

I have seen plugins that can create/generate files (.txt, .pdf, .vcard) and I'm not exactly sure how it's done. Are these done through Ajax? Or is there an object/method I'm missing?

Answer 1

Html5 does support access to File System. Below link has a good example:

http://www.html5rocks.com/en/tutorials/file/filesystem/