The release of a revised open-source toolchain for compiling unofficial iPhone applications and the advent of a jailbreak method for the iPhone 3G and iPhone OS 2.0 have breathed new life into the underground iPhone development scene. The importance of jailbreaking had been mitigated to some extent by the debut of Apple's official AppStore and waning impetus for an iPhone 3G unlock.
As reported last week, a new version of PwnageTool allows iPhone 3Gs to be jailbroken relatively easily, paving the way for installation of unofficial applications on the devices. This week, Jonathan Zdziarski and a handful of other developers ported released version 2.0 of the iPhone open source tool chain.
Unofficial developers argue that Apple's SDK is crippled with regard to much of the functionality that set the iPhone apart when first released. For instance, signed applications that run under Apple's scheme lack the ability to run in the background, as many of Apple?s own applications ? including the Mail program and Clock ? do. Unofficial applications created under the jailbreak umbrella carry no such restriction
Developers of the new toolchain update are touting the added ability to build iPhone binaries directly on devices by installing the iPhone GCC compiler.
Zdziarski told iPhone Atlas:
"This means that it doesn't matter what kind of desktop OS you run, you can still build great iPhone apps. Some changes have been made to the private API headers from v1.x to make them code-compatible with 2.0. This means most of your 1.x applications will rebuild for 2.0 with very few, if any, changes. Saurik has also provided a signing tool to sign your applications (ldid -S /path/to/binary). You'll need to do this only once to make your application run."
Zdziarski has updated his NES.app application, an emulator of the NES console, for iPhone OS 2.0. In addition, Zdziarski's book iPhone Open Application Development remains compatible with the open toolchain for iPhone OS 2.0.