Other languages
From OpenOpt
First of all let's note - you could use software like CORBA (Ada, C, C++, Lisp, Ruby, Smalltalk, Java, COBOL, PL/I, Perl, Python, Visual Basic, Erlang, Tcl) or Ice (C++, Java, .NET-languages (such as C# or Visual Basic), Objective-C, Python, PHP, and Ruby).
MATLAB/Octave/SciLab:
- NumPy_for_Matlab_Users guide
- Migration from Matlab to Python-based systems using NumPy and SciPy (doc)
- mlabwrap - a high-level Python to MATLAB bridge
- libermate - MATLAB to Python code converter
- ompc - another MATLAB to Python code converter
- pym - another MATLAB to Python code converter
.NET:
- NumPy and SciPy for IronPython / .Net (my experiments from Sep 8 show it's too premature yet)
- Ironclad - tool to run CPython modules in .NET IronPython
Excel:
- python-excel.org software list
- pyxlreader
- PythonForExcel
- PyCel - Compiling Excel spreadsheets to Python (OpenOpt usage is available)
Java:
- jpype - an effort to allow python programs full access to java class libraries
- jepp - embeds CPython in Java
- jpe - Java-Python extension
C/C++:
- shed-skin - Python to C++ compiler
- cython (Pyrex descendant) - most recommended tool for connecting C/C++ code to Python, included into NumPy
R:
- RPy - Python interface to the R Programming Language
- R-numpy - doc entry about using NumPy for R (and S+) users
OCAML:
- Pycaml
Lua:
- lupa
- lunatic-python
- pylux
Fortran:
- f2py - Fortran to Python interface generator, included into NumPy
- fwrap - a new, recently created tool, wraps Fortran code in C, Cython and Python
Assembler:
- CorePy
See also: IntegratingPythonWithOtherLanguages page from python.org
Let me also note: you can use OpenOpt + R or MATLAB/Octave code very easily via SAGE