The major changes to rbx-trepanning on gemcutter.org are:

1. code listings and rubinius llvm listings can be syntax highlighted, if
you have gems coderay and term-ansicolor installed. See
https://github.com/rocky/rbx-trepanning/wiki/Terminal-Colors for details as
to how to adjust the colors. Error messages are now in italic if
highlighting; and some commands have bold section headers. The idea for
section headers comes from the Reference debugger

2. Remote debugging has been added. This is the "server" command inside the
debugger, or the --server and --port options on the command line; --client
command-line option is used connect to an out-of-process Ruby program which
is in "sever" mode.
This was added for Wayne, but I'm not sure if that's really what he was
wanted.