Facebook Joins API Explorer Game, Sort OfAPI Explorers are proving to be an essential tool when getting up and running developing against an API.
Apigee, Salesforce, Google, Microsoft, and Infochimps have all deployed REST API Explorers to support developer integration.
The explorer lets developers specify and endpoint, and generate a JSON response, with or without an user login access token.
Developers can also use the Facebook Graph API explorer for working FQL, which is the Facebook Query Language.
Interesting that a Facebook employee was the one to develop and deploy the explorer, I'm sure its something Facebook will officially integrate into the Facebook developer area soon enough.