WSGI is a specification for web servers and application servers to communicate with web application.
The WSGI interface has
"server" or "gateway"
and
"application" or "framework".
The server invokes a callable object that is provided by the application.

WSGI is the Web Server Gateway Interface.
You can easiy install  mod_wsgi on freeBSD using ports

cd /usr/ports/www/mod_wsgi/
make
make install

Links to refer


http://www.python.org/dev/peps/pep-0333/

http://www.wsgi.org/wsgi/Learn_WSGI