You need a copy of BIND to build and install.
BIND's source code is freely available. The source code for BIND 9.2.1, the latest release of BIND 9 as of this writing, is available via anonymous FTP from ftp.isc.org as /isc/bind9/9.2.1/bind-9.2.1.tar.gz. The source code for the latest BIND 8 release, currently 8.3.3, is available from the same host as /isc/bind/src/cur/bind-8/bind-src.tar.gz.
If you're concerned about support for your operating system, you may want to check your vendor's web site to see if there's a supported patch you can apply to upgrade the version of BIND that came with your operating system to a newer version.
1.12.4 See Also
"Getting BIND" in Chapter 3 of DNS and BIND.
BIND Name Server Configuration
BIND Name Server Operations
Delegation and Registration
Interoperability and Upgrading
Resolvers and Programming
Logging and Troubleshooting