Das Unit Converter is an easy-to-use freeware program that can handle virtually all of your unit conversion needs. With over 2000 units, over 80 categories, and with the capability to add more (units; categories), you may never need to use an online converter or a search engine for unit conversions again. Some features include: Online updating, world currency, conversion history, customizable outputs, and support for math operations/functions. The portable version is the non-installer build of Das Unit Converter. Use the portable version if you want to be able to use Das Unit Converter from say, a USB disk or a memory card (so you can take it where ever you go). You can also use this version if your Windows login lacks administrative rights (since all settings are written in the local folder).