Wait, why are large sums being donated if they have half a million just sitting around? It's an open source project, not a corporation that has a millions in turnover and needs half a million as buffer for a bad year.
GIMP is obviously useful so I'm glad they have money to use, but if they are already decently covered, there are a thousand other important projects which could benefit from donations. When compared to letting half a million sit in a bank somewhere, I am wondering if this was the best purpose for the money.