Inter-application access to the local client view is not required by the specification but might be optionally supported by your container. If you want your application to be portable, you shouldn't rely on it and use a Remote interface (a decent container should optimize calls inside a same JVM anyway). From the EJB 3.1 specification:
3.2.2 Local Clients
Session beans may have local clients.
A local client is a client that is
collocated in the same JVM with the
session bean that provides the local
client view and which may be tightly
coupled to the bean. A local client of
a session bean may be another
enterprise bean or a web component.
Access to an enterprise bean through
the local client view requires the
collocation in the same JVM of both
the local client and the enterprise
bean that provides the local client
view. The local client view therefore
does not provide the location
transparency provided by the remote
client view.
Access to an enterprise bean through
the local client view is only required
to be supported for local clients
packaged within the same application
as the enterprise bean that provides
the local client view. Compliant
implementations of this specification
may optionally support access to the
local client view of an enterprise
bean from a local client packaged in a
different application. The
configuration requirements for
inter-application access to the local
client view are vendor-specific and
are outside the scope of this
specification. Applications relying on
inter-application access to the local
client view are non-portable.
...
References
- EJB 3.1 Specification
- Section 3.2.2 "Local Clients"