Apparently Octave has been orphaned by the upstream for EL5 , although it is still in Fedora Extras. It does successfully build from FC6/7 src.rpm packages under CentOS5 beta, albeit with a few additional requirements...
SRPMS: fftw-3.1.2-3.fc6.src.rpm glpk-4.13-1.fc6.src.rpm hdf5-1.6.5-7.fc7.src.rpm octave-2.9.9-1.fc6.src.rpm ufsparse-2.1.1-1.fc6.src.rpm
RPMS: fftw-3.1.2-3.el5.i386.rpm fftw-debuginfo-3.1.2-3.el5.i386.rpm fftw-devel-3.1.2-3.el5.i386.rpm glpk-debuginfo-4.13-1.el5.i386.rpm glpk-devel-4.13-1.el5.i386.rpm glpk-utils-4.13-1.el5.i386.rpm hdf5-1.6.5-7.el5.i386.rpm hdf5-debuginfo-1.6.5-7.el5.i386.rpm hdf5-devel-1.6.5-7.el5.i386.rpm octave-2.9.9-1.el5.i386.rpm octave-debuginfo-2.9.9-1.el5.i386.rpm octave-devel-2.9.9-1.el5.i386.rpm ufsparse-2.1.1-1.el5.i386.rpm ufsparse-debuginfo-2.1.1-1.el5.i386.rpm ufsparse-devel-2.1.1-1.el5.i386.rpm
Is there interest in adding this to centosplus? Or perhaps Dag or Karanbir will pick it up? I will be building it locally anyway, if it is not available elsewhere, so could help with keeping updated.
Phil