@pbrunet, I don't have tcmalloc on my system, it is not stable on OSX, so yes it IS platform dependent. Anyway you don't take the right approach, the criteria was "is it program dependent", not "is it platform dependent". My point is: if it is program dependent, it should not be in the config file.  My .pythranrc doesn't have any program specific settings and is used to configure Pythran for my OSX setup:

```
[sys]

ldflags =   -L/opt/local/lib -lboost_python-mt 
            -lgmp
            -lgmpxx 

[user]

ldflags = -fPIC -L /opt/local/lib/gcc48/
#cxx = clang++
cxx = g++-mp-4.8 
cxxflags =  -I /opt/local/include/  
#-stdlib=libc++ 
```