http://stackauth.com

{
    "api_sites": [{
        "name": "Stack Overflow",
        "logo_url": "http://sstatic.net/so/img/logo.png",
        "api_endpoint": "http://api.stackoverflow.com/",
        "site_url": "http://stackoverflow.com",
        "description": "Member of the StackExchange Network",
        "icon_url": "http://sstatic.net/so/img/apple-touch-icon.png"
    }, {
        "name": "Server Fault",
        "logo_url": "http://sstatic.net/sf/img/logo.png",
        "api_endpoint": "http://api.serverfault.com/",
        "site_url": "http://serverfault.com",
        "description": "Member of the StackExchange Network",
        "icon_url": "http://sstatic.net/sf/img/apple-touch-icon.png"
    }, {
        "name": "Super User",
        "logo_url": "http://sstatic.net/su/img/logo.png",
        "api_endpoint": "http://api.superuser.com/",
        "site_url": "http://superuser.com",
        "description": "Member of the StackExchange Network",
        "icon_url": "http://sstatic.net/su/img/apple-touch-icon.png"
    }, {
        "name": "Stack Overflow Meta",
        "logo_url": "http://sstatic.net/mso/img/logo.png",
        "api_endpoint": "http://api.meta.stackoverflow.com/",
        "site_url": "http://meta.stackoverflow.com",
        "description": "Member of the StackExchange Network",
        "icon_url": "/content/mso/img/apple-touch-icon.png"
    }, {
        "name": "Stack Apps",
        "logo_url": "http://sstatic.net/sa/img/logo.png",
        "api_endpoint": "http://api.stackapps.com/",
        "site_url": "http://stackapps.com",
        "description": "Member of the StackExchange Network",
        "icon_url": "http://sstatic.net/sa/img/apple-touch-icon.png"
    }]
}