That may be why Ford is moving slowly with opening up its Sync platform for developers. You can download apps for interacting with Twitter (OpenBeak) or Pandora, but you won't find thousands of choices. Most of the few on hand revolve around the radio, and the company is introducing Roximity, an app might have been named by Scooby-Doo but is actually used for identifying location-dependent daily deals.
General Motors is opening up an API for its OnStar service, a wireless tool that can track your car, unlock it, and even start it remotely. There's already an iPhone app, RemoteLink, and all this power could be yours if you're accepted into the program. Just write to email@example.com. The most commonly cited application is RelayRides.com, a company that helps you rent out your car when you're not using it.
This platform will expand, as car manufacturers become more confident and users become more welcoming. It doesn't hurt that a number of robot-driven cars are appearing, leaving the humans in the vehicle free to monkey around with the latest apps.
Emerging development platform No. 2: Your television
The Internet may rule the world during the day when people are connected to laptops, but it fades when people retire to the living room. Streaming services like Netflix and Hulu are making inroads, but they're still just showing unadorned video. We're a long way from a compellingly interactive item.
The most ambitious incursion of developers into the living room may be along a path paved by Google, which has had only limited success pushing its Google TV box to people on couches. Logitech and Sony manufacture them, and the API offers several avenues to get your code in front of people's eyes.
The simplest way to the TV may be to write a Web app. The TV's browser is a relatively new version of Linux Chrome, the WebKit browser that also handles Flash 10.1 content. There are small changes, and you can detect them by looking at the UserAgent string. Geolocation, for instance, isn't available.
If your website works well on Chrome, it can work well on the TV. The main challenge is dealing with the size of the screen and the UI. While many modern televisions show 1080p signals, with 1,080 lines of pixels, not many eyes can make out the small differences. You can't pack text with the same density as you can on a monitor that sits 20-some inches from a face.
Google is not limiting itself to HTML5 applications. Android developers will be able to target the living room in the future by including a separate layout. Google suggests targeting "large" tablets because the "apparent size of the Google TV screen turns out to be only slightly different from a mobile phone's screen."
There are other opportunities. XBMC is a great, open source distribution meant to turn a PC into a television command center. Its core is written in C++, but many of the add-on scripts are written in Python. Perhaps the easiest way to develop content is to create a website that delivers the content in a format that's easy for XBMC to scrape.
Other TVs offer simpler options. For example, Samsung has an API that accepts HTML5 content. It's like building a Web page, but on a bigger screen for someone who is farther away. It's available on some TVs and Blu-ray players. Yahoo has a similar item, complete with a widget marketplace where people can buy your wares.