(related variations: uu uue)

The uuencode program will convert a binary file to ASCII, typically for purposes of e-mailing. A file with this extension has usually been converted in this way and will need to be uudecoded in order to be properly used. The whole uuencoding / uudecoding thing started on UNIX systems, but today free uuencoders and uudecoders are available for virtually every computer platform. Unfortunately it was never really standardized, so sometimes uudecode on one machine will not properly work on something that was uuencoded on another.