After 3 days of frustrating trials and errors, I managed to install the new hmatrix package on Slackware 13.1. I post this message in case anyone else hits the same problem, as the process requires some alteration of the standard build process of ATLAS, LAPACK, hmatrix and hmatrix-gsl. The following steps assume that LAPACK is built against an optimized ATLAS library. 1.) By default, ATLAS builds only static libraries. However, hmatrix needs shared objects, so ATLAS should be configured with the --share option and, after the build is complete, the commands "make shared" and/ore "make ptshared" need to be issued in BUILDDIR/lib 2.) LAPACK also buils by default only static libraries and, for the same reason as above, we need position independent conde in ALL the objects in liblapack. In order to do this we need to 2.1.) Add -fPIC to OPTS, NOOPT and LOADOPT in LAPACKROOT/make.inc 2.2.) Change the BLASLIB macro in the same file to point to the optimized tatlas (os satlas) library 2.3.) Add the target liblapack.so to SRC/Makefile: ../liblapack.so: $(ALLOBJ) gfortran -shared -W1 -o $@ $(ALLOBJ) (This step is a corected version of http://theoryno3.blogspot.ro/2010/12/compiling-lapack-as-shared-library-in.h... ) 3.) Change the extra-libraries line in hmatrix.cabal to read: extra-libraries: tatlas lapack 4.) Change the extra-library line in hmatrix-gsl to read: extra-libraries: gslcblas gsl Again, this procedure worked for may Slackware 13.1 linux box, but I think it will work on any decent linux machine. Thanks everyone for your time and useful comments! Adrian Victor.