mimedecode/encode

This seem to be off topic for this list, but where I can find sources
for the tools mentioned in the subject?

--
PGP keys available via keyservers, finger or at www.rcub.bg.ac.yu/~lupusy
  Both keys are under the same UserID = 
<lupusy(_at_)afrodita(_dot_)rcub(_dot_)bg(_dot_)ac(_dot_)yu>
1024-bit RSA key  KeyID=9CCDB6E5  fpr = 08104108C9A5352B 780D9A18ED3F8A74
2048-bit RSA key  KeyID=43AC2F55  fpr = F516BC335C0BAF86 65DB67A827F266B5