Apache SpamAssassin is an extensible email filter that is used to identify spam. Once identified, the mail can then be optionally tagged as spam for later filtering. It provides a command line tool to perform filtering, a client-server system to filter large volumes of mail, and Mail::SpamAssassin, a set of Perl modules allowing Apache SpamAssassin to be used in a wide variety of email systems.
metaf2xml can download, parse, and decode aviation routine weather reports (METAR, SPECI, SAO), aerodrome forecasts (TAF), synoptic observations (SYNOP), and BUOY observations, and store the data as XML. XSLT style sheets convert it to plain language, as HTML or text. Current weather data from NOAA and other sources can be fetched and displayed.
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.
Net::DRI is an object-oriented Perl library with a uniform API to access services from domain name registries/registrars/resellers. With protocols (RRI, RRP, EPP, and XCP), it handles EU, BE, SE, PL, WS, MOBI, AERO, CAT, US, COM, NET, ORG, BIZ, INFO, COOP, LU, AT, FR, NAME, NU, ASIA, TV, CC, AU, UK, NO, DE, CH, LI, HN, SC, VC, AG, BZ, LC, MN, ME, CZ, TRAVEL, PRO, JOBS, BR, PT, SI, IM, IT, CO.CZ, TC, VG, GD, NL, AU, CA, GL, CentralNIC, and CoCCA, all with extensions. It can also perform Whois queries, domain availability checks (DAS), ENUM registrations (IENUM +43) and validations, IRIS DCHK (RFC 3981 and 5144) for .DE, and operations through the APIs of BookMyName, OVH, Gandi, AdamsNames, and OpenSRS. It also includes a shell to leverage all its power without a single line of code. It has a flexible and robust logging framework, and handles internationalization issues, DNSSEC, and IPv6.
dbMan is a complex SQL monitor for common database systems (PgSQL, Oracle, MySQL etc.). It's based on Perl and DBI interfaces. Features include a command history buffer, tab completion, editing Oracle objects, simultaneous connections, SQL help, importing and exporting of tables, Oracle explain plan, and more. dbMan is made as a simple kernel and many extension modules, and you can make your modules with a simple HOWTO.
The CentralNic Toolkit is CentralNic's system for instantaneous Registry-Registrar Communications. Registrars can use this system to register and modify CentralNic domain names in real time, with no delays for human intervention or e-mail processing. The Toolkit also provides advanced and efficient methods for searching for and querying domain names and whois records, and retrieving account information.