The makefiles, manuals, etc borrowed much from Libgcrypt written by Werner Koch.
Cryptographic functions for some SASL mechanisms uses Libgcrypt by Werner Koch et al. The NTLM mechanism uses Libntlm by Grant Edwards et al, using code from Samba written by Andrew Tridgell, and now maintained by Simon Josefsson. The KERBEROS_V5 mechanism uses Shishi by Simon Josefsson. The GSSAPI and GS2-KRB5 mechanism uses a GSS-API implementation, such as GNU GSS by Simon Josefsson.
Gnulib is used to simplify portability.
This manual borrows text from the SASL specification.