This year's keynote at Apple's Worldwide Developers Conference was a shot fired directly at naysayers claiming that a lack of new hardware signals Apple's decline.

True, Apple did not release any new gadgets. But the keynote gave the developers who ultimately will build apps for those gadgets every reason to make Apple their liege, right down to a new programming language. Along with those new tools came a long list of features carrying an implicit warning to more entrepreneurial engineers: Don't try having your own ideas and not play with us, because we will take them, we will do them better and we will crush you in the process.

>'This is something only Apple can do.'–CEO Tim Cook

To be sure, Apple CEO Tim Cook and Co. did their best Monday to make Apple feel like the biggest, most inviting, and most exciting playground ever created for coders. No announcement during the nearly two-hour presentation brought bigger whoops from the eager-to-cheer audience than Swift, a programming language created by Apple. The language is part of what Cupertino is hailing as a more visual approach to building apps.

"Swift is fast, it is modern, it is designed for safety, and it enables a level of interactivity in development that you've never seen on the platform," said Apple head of software engineering Craig Federighi, who owned the crowd with his geeky charisma.

Opening Up

While Swift is a major pitch to developers to marry themselves to Apple and its way of making apps, the company took big steps toward opening up deeper layers of its platform as well. Apps soon will be able to talk directly with one another in iOS. The TouchID fingerprint sensor on the iPhone 5s will be opened to apps beyond those made by Apple. A new graphics engine will give games direct access to the iPhone's powerful A7 chip, Federighi promised.

More important than opening up its existing devices, however, is Apple's support for the next generation of gadgets centered on health and home. Cook didn't announce any new health-tracking or smart-home devices. Instead, Apple is releasing a software foundation that ties all those devices together inside Apple devices everyone already uses.

By taking time to build the operating system layer first, Apple is seeking to assure developers that they won't have to worry about security and interoperability issues—just build cool new stuff and let Apple take care of the rest. The implied message: Apple is ready and willing to support developers building the hardware of the future.

What's Not the Future

But the company wasn't shy about telegraphing to developers what's not the future. The new iCloud Drive for file-sharing and syncing takes direct aim at Dropbox, which Steve Jobs famously wanted to buy. Even the new iCloud photo features are an open assault on Dropbox's new app Carousel for uploading and storing pictures. New features for Messages, which Federighi described as the most-used app on iOS, mimic Snapchat and WhatsApp, leading WhatsApp co-founder Jan Koum to tweet: "[V]ery flattering to see Apple 'borrow' numerous WhatsApp features into iMessage in iOS 8 #innovation."

But originality isn't Apple's priority. Any attempt to compete with Apple in a space it considers its own will be answered with Apple's comparable version. Though Apple will advertise these new self-made additions as better, the quality isn't paramount. The real advantage is that they come pre-installed.

>Any attempt to compete with Apple in a space it considers its own will be answered with Apple’s comparable version.

The recent history of mobile is full of examples of third-party apps doing Apple's version one better and succeeding. Users probably won't stop using Dropbox or Snapchat on their iPhones, just like they won't stop using Google Maps. But Apple has never been more relentless at trying to persuade the developers whose loyalty it needs that its deeply integrated collection of PCs, tablets, and smartphones is the most complete, self-contained, usable platform in existence, the one that should be foremost in their minds as they ponder which master to serve first.

At the end of the session, Cook closed the keynote with an almost defensive summation of Apple's less iterative, more closed approach to developing its products. "Apple engineers platforms, devices, and services together. We do this so we can create a seamless experience for our users that is unparalleled in the industry."

"This is something only Apple can do," Cook continued. It sounded like a promise. But it also was a warning to anyone thinking of building a startup based on a product that adds a feature that seems to be missing from Apple's platform. Rest assured, Apple was saying: it won't be missing for long.