| JSF 2.0 is the second release of JSF specification. | JSF 2.1 is the second maintainance release of JSF 2.0. |
| In JSF 2.0 there is no ease of transition from JSF 1.2. In JSF 2.0 separate declaration of facelet tag declarations are needed. | JSF 2.1 converts JSP custom tag libraries to facelet tag libraries. There is an ease of transition from JSF 1.2 to the latest version of specification. |
| JSF 2.0 does not have the feature of pluggable facelet mechanism. | JSF 2.1 has a new feature of pluggable facelet cache mechanism. |
| There is no default mapping of the Faces Servlet in JSF 2.0. | Default mapping for the Faces Servlet is done in JSF 2.1. |
