libXC
http://www.tddft.org/programs/octopus/wiki/index.php/Libxc:manual
Energy
http://www.alcf.anl.gov/~vama/madnessdocs/classXCfunctional.html#a1741d85d9afdb64d4771ebbbb78125c5
Potential
http://www.alcf.anl.gov/~vama/madnessdocs/classXCfunctional.html#a9ca458b16f8c25ca74fad7ee662c45c2
Some functional works, other doesnt
http://exciting-code.org/libxc
XCFun
Info
Git repo ( git clone git://repo.ctcc.no/xcfun )
https://repo.ctcc.no/projects/xcfun/wiki
CCLRC
ftp://ftp.dl.ac.uk/qcg/dft_library/design.html
MADxc
https://sites.google.com/site/libmadxc/
Pawel Salek's Funclib (http://www.theochem.kth.se/~pawsa/)
http://www.theochem.kth.se/~pawsa/funclib-1.0.3.tar.gz