Asynchronous DNS Resolver for Haskell is a library that provides an asynchronous DNS resolver on top of GNU ADNS. Not all options are supported, but A, MX, and PTR lookups work nicely. There is also support for retrieving generic RR types, CNAMEs, and for NSEC zone walking. The library can be expected to work with fine ADNS 1.4 or later. It might also work with version ADNS 1.3, but that hasn’t been tested.
LDAP for Haskell provides an interface to the C LDAP API for Haskell programmers. With it, you can search and modify LDAP directories. The Haskell binding features automatic memory management and proper handling for binary data, and handles all marshalling into and out of C data structures for you automatically.
linkchk is a network link ping monitor. It supports both IPv4 and IPv6. It works by repeatedly pinging a named host or the default gateway of a given interface. When the link is working the ping time is shown in a small GTK window or tty, otherwise the link status is shown. It is particularly useful for monitoring IP tunnels or dialup links.