The Date::Calc package consists of a (pure-Perl) wrapper which either loads Date::Calc::XS (a separate implementation in C and XS) or Date::Calc::PP (a pure-Perl implementation which is part of the Date::Calc package). The Date::Calc::XS and Date::Calc::PP modules perform all kinds of date calculations based on the Gregorian calendar (the one used in all Western countries today), according to relevant norms and standards: ISO/R 2015-1971, DIN 1355 and, to some extent, ISO 8601 (where applicable). The package is designed as an efficient toolbox, not a bulky ready-made application. It provides extensive documentation and examples of use, multi-language support, and special functions for business needs.
SoX is the Swiss Army knife of sound processing tools: it can convert sound files between many different file formats and audio devices, and can apply many sound effects and transformations, as well as doing basic analysis and providing input to more capable analysis and plotting tools.
The ht://Dig system is a complete WWW indexing and searching system for a domain or intranet. This system is not meant to replace the need for internet-wide search systems like Lycos, Infoseek, Google, and AltaVista. Instead, it is meant to cover the search needs for a single company, campus, or even a particular sub-section of a Web site.
Python is an interpreted, interactive, object-oriented programming language. It combines remarkable power with very clear syntax, and isn't difficult to learn. It has modules, classes, exceptions, very high level data types, and dynamic typing. There are interfaces to many system calls and libraries, as well as to various windowing systems (Tk, Mac, MFC, GTK+, Qt, wxWindows). New built-in modules are easily written in C or C++. Python is also usable as an extension language for applications that need a programmable interface.
Wcal is a Web-based calendar and planner especially suitable for multi-user setups in an intranet. It features the ability for several users to have their own or shared calendars, read-only views, Weekly and monthly repeating events. It uses the Web server's access control methods, and allows a separate access control definition for each user.