The WEB4J web app framework has been released as open source under the BSD License. (This license was chosen to make it friendly to commercial projects.) The author hopes that open sourcing WEB4J will allow it to be considered by a much wider audience than previously possible. Any suggestions for improvement of the tool are always welcome. Regards, John O'Hanley (creator of web4j).

I've been following your project. Thank you for your effort.

How Web4j handles sessions to support multiple users?

It simply uses HttpSession objects - part of the Servlet API. In addition, there are some simple convenience methods available to Actions, to allow reading/writing objects to the user's session. There are also simple ways of storing error messages and information messages in session scope (which allows such messages to survive redirect operations). Is there perhaps a more specific use case you are concerned with? - John

Coming from WebObjects and Tapestry background, I was wondering whether Action created for a jsp page has session scope by default or Action object has request scope and any session specific logic need to be coded in Action.

Here is an example of a typical Action. There is usually no default scope. In the Action, you explicitly call addToRequest or addToSession, according to need (see the ActionImpl class). The only exception to that rule is error and information messages passed to the addError and addMessage methods: such messages are always placed in session scope by ActionImpl, since they often need to survive a redirect.