About a month ago a big shot from Microsoft came to speak at the university - looks like he's on some kind of a tour, and his mission is to convince universities to teach Windows operating system aside Unix/Linux. He waved at the audience with a free license and tried very hard to prove that some aspects of Windows design are better than Unix, mainly because it is "newer" design and better suited for nowadays computers.
Long story short, one of the things he said, was that open source is bad, because engineer who looks at the source of a library will design his application assuming particular implementation, which is now tightly coupled to library internals - bad. Obviously a discussion erupted - design by contract and Eiffel were thrown in the air, relation between programming language and operating systems..., but frankly all I could think of is my distant past as a VB developer and those 1000 pages "Windows *** Unleashed" books. They were written by hackers who used trial-and-error against Windows DLLs trying to make some sense of the APIs - the formal documentation was either sloppy or intentionally incorrect to misguide us, Windows application creators outside Microsoft, since we were potential competitors. Things were so different when I moved to Java. (Though my first Swing experience made me - believe it or not - miss VB, but that's another story.)
Anyway, statement like this coming out of the mouth of a Microsoft employee, even if he has an impressive Unix record, was easy for me to dismiss. But here is a respected Smalltalker saying
"I think people should have the source ...not to get miss quoted saying I'm against open source, but I think it's important class libraries should be viewed like caves."(Ah, wait, he is from IBM - he can be ignored too... just kidding)
I mean, seriously look at this puzzler for example - it's pretty cool, but the solution heavily relies on a particular implementation, I would even say this is actually a hack. And sometimes a hack is necessary... or is it? Is there or will there ever be a perfect environment where we can program without hacking?
P.S. The reference to Ali Baba tale in the title is intentional. Open source is good, very good, it's a treasure and in the world dominated by large corporations - almost a miracle. But IMO we should resist the temptation to exploit it to the last bit, because we might find ourselves locked in the cave.