Following the instruction of "Creating XPCOM components", I was able to create the required .so along with .xpt .idl file. But browsing through full sdk I was not able to find out a location where I need to put these files and How to know that if this developed component is working well.
Also for excersizing your component in a smaller environment XPCShell works well. XPCShell is a command line JS interpreter. It's documented here http://www.mozilla.org/scriptable/XPCShell.html
David
