Interoperability is a key element in software today. You often read about how many big organizations that still try to build the famous 1-big-system-that-does-it-all. And those projects always fail. Even if they 'succeed' it's usually still a failure cause the system is outdated the moment it reaches production.
The trick to success is as always: divide and conquer. Use the best software for each task - and ensure the systems can work together. This is where API's come into play, and in CodeArt we have done our fair share of them.