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.
hsclock is an accurate, multi-zone GTK clock that can also run in a tty. Currently configuration is solely by commandline options. hsclock uses GTK timeouts to synchronize with the system clock, making display updates accurate to within milliseconds. The time output format can be set with a date-like format option.
Parsec is a monadic parser combinator library for Haskell. It can parse context-sensitive, infinite look-ahead grammars but performs best on predictive (LL) grammars. The parser definition is in the same language as the rest of the program, so it benefits from type checking and existing development tools. Parsers are first-class values within the language and it is easy to extend the set of parsers with custom-made ones.
Riot is a tool for keeping (textual) information organised. It is a todo list and note manager, and a manager for whatever information one might collect. It has an interface resembling those of slrn and mutt and all text editing is done with an external editor, making it a nice browser for collections of text.