An interface compiler that connects programs
Edit by : WIG is an interface compiler that connects programs written in C and C++ with scripting languages such as Perl, Python, Ruby, and Tcl. It works by taking the declarations found in C/C++ header files and using them to generate the wrapper code that scripting languages need to access the underlying C/C++ code. In addition, SWIG provides a variety of customization features that let you tailor the wrapping process to suit your application.

John Ousterhout (creator of Tcl) has written a paper that describes the benefits of scripting languages. SWIG makes it fairly easy to Connect scripting languages with C/C++ code.

SWIG is used in a number of ways:

Building more powerful C/C++ programs. Using SWIG, you can replace the main() function of a C program with a scripting interpreter from which you can control the application. This adds quite a lot of flexibility and makes the program programmable. That is, the scripting interface allows users and developers to easily modify the behavior of the program without having to modify low-level C/C++ code. The benefits of this are numerous. In FACT think of all of the large software packages that you use every day---nearly all of them include special a macro language, configuration language, or even a scripting engine that allows users to make customizations.

Rapid prototyping and debugging. SWIG allows C/C++ programs to be placed in a scripting environment that can be used for testing and debugging. For example, you might test a library with a collection of scripts or use the scripting interpreter as an interactive debugger. Since SWIG requires no modifications to the underlying C/C++ code, it can be used even if the final product does not rely upon scripting you can free download SWIG 1.3.40 now.