re:Where is the "Tools" menu, to connect to other worlds?

There are several icons in the Croquet pane of the green objects catalog.  These icons represent different demonstrations of the core Croquet functionality, and they vary in some aspects.

The Croquet and Demo (Master and Participant) worlds have a different form of menus, which largely IS just the Morphic halo (one of them also has a navigator menu which can be brought up by putting the mouse pointer near the bottom of the Croquet morph).  The way that these demos are built, they only search within their local LAN subnet for potential partners.  The Master assumes that it is the only master, and the Participant looks for the master to join.  There are some parameters coded in the setup that determine the name of the party for both master/host and participant/guest.

Some of the other demos, like the Sailing and SimpleDemo worlds have top-of-the-screen menu bars that have the join function.  These show one or two ways to allow party joining over the Internet.

I think Howard Stearns wrote a few more details sometime within the last few weeks about how the Croquet logical routers differ to allow for these different connection strategies, if you want to look for that on this list.  Or maybe it was on the Croquet-developer list.