Hi, I'm trying to compile a software which links your PPL library, but at the linking step I got the error: Undefined symbols for architecture x86_64 .... ld: symbol(s) not found for architecture x86_64 Here is my box configuration: MacBook Pro OS X Yosemite 10.10.3 gcc/mp-4.7 MacPorts 2.3.3 PPL 1.1 (installed by MacPorts) The installed libraries are located in /opt/local/lib: libppl.13.dylib libppl.a libppl.dylib libppl_c.4.dylib libppl_c.a libppl_c.dylib and the link options are -L/opt/local/lib -lppl I really cannot figure out why the library does not support the x86_64 architecture, because MacPorts had no problems at all in installing your library. It would be really nice if you could help me, since the code is for a research project. Looking forward to hearing from you as soon as possible Gaetano