This is great, a lot of the performance in BLAS comes from memory management. This does not solve my problem though. Sometimes you want to manually control memory, and Julia does not make it easy to do so. In particular when interfacing with BLAS/LAPACK though Julia, memory management is quite ugly, mainly due to the need for allocating work arrays, and a pure Julia implementation of BLAS is unlikely to fix this. I don't think writing eg ARPACK performantly in Julia is imposible, just painful to the point that writing it in FORTRAN starts to make sense (to me).