mdp stands for "Mot de Passe", which means "password" in French. It wraps GnuPG for encryption and deals with all the small details of generating, managing, and fetching your passwords. It is similar to many other programs, but differentiates itself with simplicity (not button-driven simplicity, but with a Unix less-is-more style). For example, beyond the use of GnuPG for encryption, it lets you use your own editor to manage your passwords, categorize them, and delete them. In order to avoid passwords lingering on your screen, the results from the queries are displayed through a custom pager which is cleared after a customizable timeout (defaulting to ten seconds).
mDNS Responder with Unicast runs on a server anywhere in a network and responds to mDNS queries across the network by performing a unicast DNS lookup and returning the result. Many networks use a .local top-level domain for their intranet. This has proven to be quite problematic as operating systems such as OS X have begun handling .local domains differently (in particular, prioritizing multicast DNS over conventional unicast DNS). Ideally, you'd have no problems moving away from a .local domain name, or simply not using one in the first place. That's not always possible, though. So with this tool, a lookup for "host.local" will be resolved via your existing unicast DNS servers, even if "host" does not have its own mDNS responder. Of course, the tool isn't limited to just .local domains, and can realistically work on any network where mDNS is in use.