From the FAQ: Why Pure? Thanks to LLVM, Pure offers state-of-the-art JIT compiler technology in an interactive environment, and makes it easy to interface to

From the FAQ: Why Pure? Thanks to LLVM, Pure offers state-of-the-art JIT compiler technology in an interactive environment, and makes it easy to interface to C in a direct fashion. Recent releases also provide the ability to directly import LLVM bitcode modules into Pure scripts and to inline code written in various languages (currently C/C++, Fortran and Faust). Scripts can also be compiled to standalone native executables (they are also executed during compilation, which makes it possible to employ partial evaluation techniques). Pure has an efficient MATLAB-like, GSL-compatible matrix type which makes it easy to interface to languages and libraries for doing numeric computations and digital signal processing. In particular, Pure interfaces to (GNU) Fortran, Octave and Grame's Faust, and you can directly invoke GSL routines on Pure matrices. In a way, this is like having Haskell, Octave, DSP programming and the term rewriting capabilities of a computer algebra system under one hood. It goes without saying that Pure can be used used for mathematical applications, but there's also a growing collection of extension modules for GUI, graphics, multimedia, database and web programming which makes Pure useful as a kind of algebraic/functional scripting language for a variety of purposes.