fireparse is an ADMLogger plugin that emails a report of all packets that have been logged by the kernel's packet filtering subsystem (iptables/netfilter or ipchains). The report includes source and destination ports, direction, logged packet count, matched rule, and fully resolved host names (if available). The email report can be formatted to plain text or a colored HTML table.
The Fink project wants to bring the full world of Unix Open Source software to Darwin and Mac OS X. It modifies Unix software so that it compiles and runs on Mac OS X and makes it available for download as a coherent distribution. Fink uses Debian tools like dpkg and apt-get to provide powerful binary package management. You can choose whether you want to download precompiled binary packages or build everything from source.
This is a much updated version of Mike Shanzer's fingerd-1.3. It is almost completely rewritten, well-debugged (i.e., more secure), and quite configurable. It supports ACLs, a message-of-the-day file, the ability to run programs for given user-IDs, and a full set of command-line options that make it mostly compatible with modern BSD versions. It is portable, uses GNU Autoconf and GNU Automake for builds, and it comes with a ready-to-use BSD makefile too.
findimagedupes is a command-line utility which performs a rough "visual diff" on two images or a whole tree to detect if any look similar. It can produce output suitable for driving GUI front-ends. It can also export a GQView compatible collection file, so you can deal with the duplicates visually. On common image types, findimagedupes seems to be around 98% accurate.
Finance::Quote is a Perl module which can fetch on-line stock quotes, including those from American, European, Canadian and Australian markets. Information from a number of investment houses is also available. Features include currency lookups and conversions, automatic failover support, and loadable user modules.