Optimization of the CMS software build and distribution system

CMS software consists of over two million lines of code actively developed by hundreds of developers from all around the world. Optimal build, release and distribution of such a large-scale system for production and analysis activities for hundreds of sites and multiple platforms are quite a challenge. Its dependency on more than one hundred external tools makes its build and distribution more complex. We describe how parallel building of the software and minimalizing the size of the distribution dramatically reduced the time gap between software build and installation on remote sites, and how producing few big binary products, instead of thousands small ones, helped finding out some integration and runtime issues of the software.