Hi,

There is no "standard" salesforce.com schema to publish, as the schema changes depending on your login credentials and how your administrator has setup your system.
In the view which you supply, there are a few fields which end with "__c", e.g. TrackingNumber__c. These are custom fields which are available to your salesforce.com login because your admin has created them
These fields are not available to other salesforce.com users, either because they are in a different "org" or because field level security dictates that they do no have privilege to see them.

Other fields may be exposed depending on which features have been enabled for your org, e.g. orgs which have multi-currency support will have an field called IsoCurrencyCode for every currency field. Orgs which have self-service enabled will have extra fields on contact records.

As well as this field level security, your administrator can restrict access to entire objects, so the opportunity "table" may be visible to sales users, but not support users.