PLETHORA is a measurement unit conversions calculator that is more powerful than ANY unit conversion program or online conversion utility available! PLETHORA has many hundreds of metric/S.I., imperial, U.S., and other units in its database, most to 14 significant digit precision. New units can be easily added by the user. PLETHORA Supports compound units such as pounds and ounces, ft/in/fractions, scientific notation and control of significant digits. PLETHORA can also convert clock times and many physical constants. PLETHORA also contains an extensive database of definitions and discussion on measurement systems an their history and proper usage. PLETHORA is the most comprehensive and educational unit conversion software on any platform. It is an ideal tool for any person, business, or organization needing to carry out measurement conversions of any type. PLETHORA is also an excellent educational reference for all levels, with on-line bibliography and sections on the history and methodology of measurement, as well as built in definitions for most units and unit groupings.