The IMF is the International Monetary Fund. This is a fund that allows countries to borrow at times when they have a great need. Various countries of the world pay money into the fund and the fund lends it when needed. For example, the IMF has recently lent money to Greece because that country is having terrible problems paying off its debts. There cannot really be any examples of the IMF itself, but there are examples, like this one, of actions that the IMF takes.
The implication of the IMF is that it tends to impose certain conditions on countries that borrow from it. The implication of this is that it has the power to force countries to act in certain ways if they want to borrow money that they badly need. Typically, the IMF tries to require countries to cut back on governmental spending and to improve the ways in which their governments are run. What this means is that countries tend to feel that the IMF if coercing them into acting in ways that the Western rich democracies want them to act. Therefore, the IMF tends to be controversial with many people.