Two types of software packages are available for download - the precompiled and source distribution. Currently only relaxation curve-fitting requires compilation to function and all other features of relax will be fully functional without compilation. If relaxation curve-fitting is required but no precompiled version of relax exists for your operating system or architecture then, if a C compiler is present, the C code can be compiled into the shared objects files *.so, *.pyd or *.dylib which are loaded as modules into relax. To build these modules the Scons system from http://scons.org/ is required. This software requires the Python and numpy header files installed. Once Scons is installed type
in the base directory where relax has been installed and the C modules should, hopefully, compile without any problems. Otherwise please submit a bug report to the bug tracker.