This is Coin-@VERSION@ by Systems in Motion. What you have downloaded
is only the framework itself, provided as a convienience for those who
do not want to use binary installers. To install, simply drag the
Inventor.framework to /Library/Frameworks. If you prefer, you can also
find a complete package including an installer and the Coin 
commandline tools on our ftp server[0]. 

Note that this binary SDK has been built with gcc 3.3, meaning
that no earlier version of gcc should be used in combination with 
this framework. The framework is, however, built with 
MACOS_DEPLOYMENT_TARGET=10.2 to be deployable on 10.2 (Jaguar) or
later versions of Mac OS X.

The Coin3D/Mac homepage[2] contains more information on how to get
started using Coin. You might also want to consider joining our 
public mailing list for discussions related to Coin3D development[3].

Enjoy!

[0] ftp://ftp.coin3d.org/pub/coin/bin/macosx/
[1] http://www.coin3d.org/mac/faq/#dist_tiger
[2] http://www.coin3d.org/mac/
[3] https://www.coin3d.org/mailman/listinfo/coin-discuss/