EnDE

[sowhat-x]

"Encoder, Decoder, Converter, Calculator...for various codings used in the wild wide web"
Not really a need to say more...as you can check for yourself the online version here:
http://ende.my-stp.net/EnDe.html

For offline downloadable package (app written 100% in JavaScript),manual etc...
http://ende.my-stp.net/