Is Whisper Systems a charity, non-profit or a commercial entity? If it's either of first two, then it would've only make sense to say just that in the About section, because it would alleviate all questions of why their products are free. However if it's a commercial entity, the question remains - how do they plan on making money? And donations is a silly answer. They are a nice bonus, but as any goodwill gestures they are an unsustainable and unpredictable source of money unless there are dedicated people managing it, e.g. organizing fundraisers, campaigns and such. I don't think WS is doing any of this.