"Smart monkey" joke

A tourist walked into a pet shop and was looking at the animals on display.
While he was there, another customer walked in and said to the shopkeeper, "I'll have a C monkey please."
The shopkeeper nodded, went over to a cage at the side of the shop and took out a monkey.
He fit a collar and leash, handed it to the customer, saying, that'll be $5000." The customer paid and walked out with his monkey.
Startled, the tourist went over to the shopkeeper and said, "That was a very expensive monkey. Why did it cost so much?"
The shopkeeper answered, "Ah, that monkey can program in C very fast, tight code, no bugs, well worth the money."
The tourist looked at the monkey in another cage. "That one's even more expensive! $10, 000!
What does it do?"
"Oh, that one's a C++ monkey; it can manage object- oriented programming, Visual C++, even some Java. All the really useful stuff," said the shopkeeper.
The tourist looked around for a little longer and saw a third monkey in a cage of its own.
The price tag around its neck read $50, 000.
He gasped to the shopkeeper, "That one costs more than all the other put together! What on earth does it do?"
The shopkeeper replied, "Well, I haven't actually seen it doing anything, but the other monkeys call him the project manager."