Echo3 is the next generation of the Echo framework. It nearly retains the API of Echo2 for end developers, but provides a new web container layer that offers superior performance and extensibility. The new web container also provides the capability to write Echo applications entirely in client-side JavaScript using an API patterned after that used to write server-side Echo applications (using this API is entirely optional, Echo3 applications may also be written entirely in server-side Java).

Porting from Echo2 to Echo3

See http://echo.nextapp.com/site/echo3/doc/migration for migration documentation.

The end-developer API is nearly identical to Echo2, though modification of Echo-based projects will be necessary due to a package-name change from a "nextapp.echo2." prefix to "nextapp.echo." Such "porting" work is substantially less difficult than it was to port Echo1 projects to Echo2, as APIs have been kept intact with very minor exceptions.

At the time of this writing, neither Echo3 nor Echo3Extras are complete. In the case of Echo3Extras, some components are missing. If however the components your application requires are currently present in Echo3/Extras, it may be possible to simply do a search and replace on "nextapp.echo2." with "nextapp.echo.", compile, and run.

Components that render custom HTML and JavaScript will need to be rebuilt for the new web container. The bad news here is that this is an entirely new API. The good news is that its substantially easier to work with, more capable, and more efficient than the outgoing one. Additionally, many tasks are taken care of for the developer (e.g., client-server serialization of component state).

License

Echo3 and Echo3Extras are licensed under the Mozilla Public License (MPL). Optionally, the user can license the software under the GNU Lesser/Library General Public License (LGPL) or the GNU General Public License (GPL).

Source Code Access

The following Echo3 source code repositories are available:

Core Echo3 Framework: svn://svn.nextapp.com/echo3/trunk

Echo3Extras Project: svn://svn.nextapp.com/echo3extras/trunk