[CentOS] Difference between ruby193 CentOS SCL and ruby193 softwarecollections.org SCL

I've found that in https://softwarecollections.org/repos/rhscl/ruby193/epel-6-x86_64/ is passenger included but in http://dev.centos.org/centos/6/SCL/x86_64/ruby193/ is not.
What is the differences between this two repos?
 
Thanks,
Filip Bartmann