Different methods for requesting data from server with authentication

If I am interested in creating a web application that fetches user data f开发者_开发问答rom a server with authentication (using the Google Picasa API to get private Picasa web albums, for example), what are the different languages and methods I would use to accomplish this? Is it possible with Javascript? To start, I know this:

PHP: the cURL library

Any resources online that might give a better idea of the concepts behind this are welcome as well!

See http://code.google.com/apis/gdata/docs/developers-guide.html, section "Versions of the protocol"