According to wikipedia, the LLVM is licensed using the University of Illinois/NCSA Open Source License. http://en.wikipedia.org/wiki/University_of_Illinois/NCSA_Ope...
As stated in that entry, "Source code under the NCSA license can be incorporated into proprietary products without the reciprocity requirements that copyleft free software licenses raise. The license is compatible with all versions of the GNU General Public License."
Can someone smarter than me explain how this license undermines freedom? Or how the LLVM undermines freedom despite this license? I'm having a hard time connecting the dots.