yum the rpm package manager is now available for AIX opensource Toolbox.
It allows automatic package installation, updates and dependency management.
For installing yum on AIX
1. Install the rpm.rte with "minimum version" of 18.104.22.168 or greater from ftp://ftp.software.ibm.com/aix/freeSoftware/aixtoolbox/INSTALLP/ppc/
2. Download and install the rpms from yum_bundle_v1.tar from ftp://ftp.software.ibm.com/aix/freeSoftware/aixtoolbox/ezinstall/ppc/
This bundle contains yum and all of it's dependency rpms.
Please go through README-yum from following location for detailed description and known issues of yum on AIX.