SAML 1.1/SAML 2.0 is the default token format when using ACS as the authentication service for your website. In this model, your website talks to ACS using WS-Federation protocol and what it normally gets back is a Saml token. This scenarios is fairly straight-forward as WIF natively supports WS-Federation protocol & SAML1.1/SAML 2.0 token formats.
There are cases where you might want to return a Simple Web Tokens (SWT) after a successful authentication. For example, you might want to use this same SWT (available as a bootstrap token) to call other downstream REST/OData services as depicted in the following diagram.
ACS fully supports returning an SWT token after a successfully WS-Fed authentication but WIF currently doesn’t support SWT tokens. You would have to write a custom Security Token Handler for WIF to process SWT tokens coming back to your website. I have created some extensions which enables this and other OAuth WRAP related scenarios. Feel free to download the code from my SkyDrive.
There are cases where you might want to return a Simple Web Tokens (SWT) after a successful authentication. For example, you might want to use this same SWT (available as a bootstrap token) to call other downstream REST/OData services as depicted in the following diagram.
ACS fully supports returning an SWT token after a successfully WS-Fed authentication but WIF currently doesn’t support SWT tokens. You would have to write a custom Security Token Handler for WIF to process SWT tokens coming back to your website. I have created some extensions which enables this and other OAuth WRAP related scenarios. Feel free to download the code from my SkyDrive.
More Here
Courtesy:http://zamd.net/2011/02/08/using-simple-web-token-swt-with-wif/