I am somewhat confused by the facebook developers guide. Some tutorials show the javascript SDK being used while some show the PHP SDK being used. Do I need to load both of these? Are there any differences between the two (besides one being client and one being server)?
I am wanting to use Facebook’s SDK for User Authentication, Social Plugins, and the Graph API.
The best advice I can give you – be very careful when planning a new development on the Facebook Platform. A lot of the documentation is seriously out of date, and this is exacerbated by sporadic platform revisions.
Admittedly, this has improved in recent months, but I digress…
Facebook have recently deprecated the creation of FBML canvas applications, which means your application will have to be in an iframe. This also implies you could make the applications available off of Facebook too (e.g., http://apps.facebook.com/someapp/ and http://www.someapp.com/ can both load up). This narrows the benefits of using the PHP SDK, as a lot of the functionality is available via the JavaScript API.