But it is not all. Open Source definition is a very broad definition, and some software packages may not be usable at all without proprietary, closed and well-controlled companions. In that light, building from source is the ultimate indicator whether a software creator really gives you the right to build (and, what's more important, to patch) his/her code.
- Security: Pre-packaged program binaries and program libraries not built from the source code could contain parts that are malicious, dangerous, or just broken. Also, these are functionally impossible to patch.
- Compiler Flags: Pre-packaged program binaries and program libraries not built from the source code were probably not compiled with standard Fedora compiler flags for security and optimization.
This post was inspired by this answer on fedora-java.