Developers need certainty when they invest time and money into applications. The early history of the Macintosh shows that when you combine intense company support, a clear process, and great excitement - that is, Guy Kawasaki and his amazing evangelical efforts - you can build an ecosystem that sustains a platform.

Jason Snell, Macworld's editorial director, writes that Apple's lack of transparency, consistency, and clarity in how they approve or reject applications for the App Store for iPhone and iPod touch may lead to developers reaching a point where they walk away.

The most recent absurd decision, in which Apple denied distribution to an on-the-fly podcasting management program because it duplicated "the functionality of the Podcast section of iTunes" has had a clearly chilling effect when you follow developers on Twitter, and read developers' blogs.

True, many of these firms that are candid about their plans are on a relatively small scale, but they also make some of the best and most popular software outside design and business suites. Smaller developers have a disproportionate impact on Mac OS X as a desirable platform compared to, say, the same scale of programmer or firm on Windows; due to Windows' large market share and base, enormous firms making games and business applications seem to hold the greatest sway. (This is a generalization, but it's based on years of interaction with regular Mac users, these various companies' volume of products sold, and the kind of purposes to which Macs are more frequently put than their Windows counterparts.)

I'm currently in the middle of my own small iPhone application development project. I'm investing some thousands of dollars in having a programmer build the application and hiring a designer to create an application icon, and I have put over 100 hours of my time into revising the back-end of the hosting side of the equation. (The app will be a portable way to check on book prices through my book shopping site isbn.nu. Many of the changes made to the Web site and its database-driven system will also benefit its Web-only component.)

I admit that as a very small scale "developer" - I even have to put that word in quotation marks - I had to put on an extra sweater. As my family's breadwinner, investing hours and dollars is a scary thing when Apple might suddenly decide that, say, shopping applications aren't allowed, even though there's nothing either competitive or against the guidelines issued.

On a much larger scale, why would a gaming firm that doesn't have a direct relationship with Apple put $50,000 into creating a game for the iPhone if Apple could snap their fingers and prevent the game from being sold? Or why should a one-person shop put a single penny in? A larger firm might absorb the loss and move on; it could destroy the small companies that make the Mac so rich to use.

Jason notes that the Google-backed Android platform apparently has no restrictions on what can be added to its Market application store, although at launch, all programs must be free to download (see "T-Mobile Introduces Branded Google Phone," 2008-09-23). That may not be tenable, but it's part of the open access principles Google has been putting their weight behind for more than a year: networks should accept any handset running any software accessing any service.

Let's not get into a tussle about whether Android will actually thrive as a platform; Nokia also has an active, expanding, and far more open process for applications to be distributed for its Symbian and S60 platforms (see "Symbian Smartphone Platform Goes Free, Partly Open Source," 2008-06-24). If there's a comparable platform that's more open for development and has a large audience (Symbian has the majority of smartphone sales worldwide), then developers whose future is in mobile applications may migrate to it, however irritating it is.

Apple needs to get its act together to avoid uncertainty by being specific about what is and isn't acceptable. Remember FUD? Fear, uncertainty, doubt. It was what once made Microsoft great and terrible: they sowed FUD to keep their competitors from gaining a toehold.

But Apple's FUD is against themselves. They need to unFUD themselves, and fast.