pkg://cyrus-sasl-2.1.18-2.src.rpm:11237438/README.RPM  info  downloads

Note that this package includes both 1.5.x and 2.x versions of the Cyrus
SASL library.  This is possible because they are (for the most part) installable
in parallel [*].  At some future date, the 1.5.x support will be removed.

New development should be targetted to the 2.0.x library, using header files
in /usr/include/sasl, the libsasl2 library, and the /etc/sasldb2 sasldb.

If you are upgrading from a system with Cyrus SASL 1.5.x installed, the
dbconverter-2 tool can be used to extract secrets from an existing sasldb
and store them in a sasldb2.

* An exception is that the saslauthd protocols are different, so v1 clients
  can't use the included saslauthd for authentication.