These are a few IPv6 toys I cooked up to solve problems.

wrapper is a moral equivelant of tcp_wrappers. It's missing most of the
nice extra features of the real thing, not to mention the rigorous testing.

addrform is a simple program designed to be used with v6wrapper that
transforms the socket address to the specified family and then execs the
specified daemon. It's main use is to downgrade IPv4-mapped addresses to
real IPv4 addresses.

These programs REQUIRE the NRL support library.
