  The MIME (Multipurpose Internet Mail Extensions) specification (RFC 1341
and successors) defines a mechanism for encoding arbitrary binary information
for transmission by electronic mail.  Triplets of 8-bit octets are encoded as
groups of four characters, each representing 6 bits of the source 24 bits.
Only characters present in all variants of ASCII and EBCDIC are used, avoiding
incompatibilities in other forms of encoding such as uuencode/uudecode.

  base64 is a command line utility which encodes and decodes files in this
format.  It can be used within a pipeline as an encoding or decoding filter,
and is most commonly used in this manner as part of an automated mail
processing system.

Homepage:
https://www.fourmilab.ch/webtools/base64/
