Sharing a transaction between programs.

I'd like to have two programs cooperating, each implementing a different module
of an application. I'd also wish they perform a single transaction (I'd use
distributed transaction if they were available). As this two application would
probably be written in different programming languages, I'd like to do something
like.

App1:
    connect to the db;
    begin transaction;
    do work;
    call app2 (app1 passes a 'handler' to the transaction to app2)
    commit;

App2:
    receive 'connection handler';
    do work;


Is this (or something similar) possible?

Thanks!


Fernando.