abcde is a frontend to cdparanoia, wget, cd-discid, id3, and your favorite Ogg Vorbis (the default), MP3, FLAC, Ogg Speex, or MPP (Musepack) encoder. It grabs an entire CD and converts each track to the desired format, then comments or ID3-tags each file, all with one command. It supports multiple output in a single CD read, the creation of a single track from a CD, resume operation, CD concatenation, volume normalization, gapless encoding (with LAME), parallelization, SMP, proxies, customizable filename organization and munging, playlist generation, distributed encoding via distmp3, and more.
acmemail is a multiuser IMAP/POP3 to Web gateway (or webmail program). It reads mail from a mail server and displays it using HTML on a web server. It is written in Perl, has full support for MIME (and mod_perl), is quite pretty, and is GPL'd or distributed under the Perl Artistic License.
aee is a text editor that is intended to be usable with little or no instruction. It provides both a terminal (curses based) interface and native X-Windows interface (in which case the executable is called xae). Features include pop-up menus, journalling (to recover from system crash or loss of connection), cut-and-paste, multiple buffers (associated with files or not), and much more.
AFT (Almost Free Text) is a document preparation system. It is mostly free form, meaning that there is little intrusive markup; AFT source documents look a lot like plain old ASCII text. It has a few rules for structuring your document, more to do with formatting your text than embedding lots of commands, and it produces all types of output (HTML, XHTML, LaTeX, roll-your-own XML, etc.). All that needs to be done is to edit a rule file. You can even customize your own rule files for specialized output.
Algorithm::Diff is a Perl module for computing the difference between two files, two strings, or any other two lists of things. It uses an intelligent algorithm similar to (or identical to) the one used by the Unix `diff' program. It is guaranteed to find the smallest possible set of differences.
The anpa utility takes a newswire service feed (ie. AP, UPI, BayCity, SportsTicker) that conforms to the ANPA 1312 specification from a tty or file and outputs an IETF RFC-822 (mail.local or rmail) style file that can be injected into some data stream like USENET or Internet mail. It can also do things like send the article to printers, fax machines, pagers or run any application such as one that would toggle a data line on a printer port to turn on and off a lamp via a solid state relay.
Aphid (the Apache/Perl HTTP Installation Daemon) provides a quick facility for compiling and installing the Apache Web server with support for SSL via mod_ssl, and with the embedded Perl interpreter provided by mod_perl. It downloads, compiles, and installs the software into the directory of your choice. Aphid places emphasis on providing an intuitive, browser-based interface and keeping a tiny distribution footprint. To date Aphid has been tested on Rehat Linux 6 and 6.2, FreeBSD 4.0, and Solaris 2.6 and 7.