binascii is a Common Lisp library for converting binary data to ASCII text of some kind. Such conversions are common in email protocols (for encoding attachments to support old non-8-bit clean transports) or encoding binary data in HTTP and XML applications. binascii supports the encodings described in RFC 4648: base64, base32, base16, and variants. It also supports base85, used in Adobe's PostScript and PDF document formats, and a variant called ascii85, used by git for binary diff files. It is documented, flexible, and fast, and comes with a BSD license.