How to interface two API written in different language?

How to interface two API written in different language?

References

Reference NO 1

http://stackoverflow.com/questions/15193738/how-to-interface-two-api-written-in-different-language

Reference NO 2

http://en.wikipedia.org/wiki/Application_programming_interface

Reference NO 3

http://www.acm.org/tsc/apis.html

Reference NO 4

http://c2.com/cgi/wiki?ApiVsProtocol

Reference NO 5

http://www.mathworks.com/help/matlab/external-interfaces.html

Reference NO 6

http://publib.boulder.ibm.com/infocenter/txformp/v6r0m0/topic/com.ibm.cics.te.doc/erziaz0049.htm

Reference NO 7

http://www.cs.columbia.edu/~hgs/teaching/ap/examples/scripts_python_dbapi.pdf

Reference NO 8

https://doc.openerp.com/v6.1/developer/12_api/