Getting the iPhone Open Source Tool Chain Up and Running(让iPhone开源工具链发展起来)

Tomorrow at 10 am pacific time, oreilly.com is hosting a free webcast with Jonathan A. Zdziarski, one of the original hackers of the iPhone and author of iPhone Open Application Development. From the announcement:

Jonathan will demonstrate how you can use the iPhone open source tool chain to design third-party software that will run on on both today's iPhones, and on iPhones that will soon be running Apple's next version of firmware based on the official SDK. Jonathan will demonstrate on a Mac running Leopard.

Introducing Jonathan will be Brian Jepson, executive editor for Make Magazine's Make:Books series, co-author of Mac OS X Tiger for Unix Geeks and a number of other geeky books, and iPhone hacker at large.

This is your opportunity to hear expert advice on building applications for the iPhone and ask questions of the experts themselves.

Attendance is limited, so register now. We'll send you a reminder before the webcast.

Date: Thursday, April 3 at 10am PDT (17:00 GMT)
Cost: Free
Duration: 30-45 minutes
Meeting link: oreilly.com/go/webcast-iphone
Teleconference dial-in:
(select the number that is closest to your location)
East Coast US: +1 617 231-0350 and pin 8136507
West Coast US: +1 213-455-0500 and pin 8136507

Some people might wonder why we published a book on the open source toolchain when an official SDK has already been announced. (I wondered that myself We started the book before Apple had learned from the first hackers that people wanted more out of the phone and announced the open API. But why didn't we just hold off on publishing it, modify it for the official API, and release it when the time comes (supposedly sometime in June) when the official API is open for business? The answer is threefold.

1. We believe strongly that hackers mark off the natural paths that official developer programs later pave over and make safe for the less adventurous. Smart companies know this, and pay attention to their hackers. (Google Maps is a great case in point. It became the mapping platform of choice because, rather than shutting down the early mashup hackers, it quickly figured how to pour fuel on the fire that they'd started.) We think that despite the official disapproval, Apple knows that the hacker interest in the iPhone is a great boost to their program and their goals. (Witness the fact that the Apple store in Cambridge MA allowed Jonathan to present on open iPhone development in a meeting at the store.)

2. The open API has a great deal of overlap with the official API. So getting up and running with the open toolchain will help developers get a head start. But it's also more powerful than the official toolchain, and will let developers continue to push Apple in interesting new directions. Jonathan wrote:

With the introduction of the Apple SDK, developers gauged its functionality based on a comparison to the unofficial, open source SDK released last August. In the process of building this custom, open source compiler for the iPhone, the development community exposed the many low-level APIs (application programming interfaces) available on the device. Using tools such as class-dump, nm, and just plain old trial-and-error gave developers access to the full breadth of functionality available deep within the iPhone's frameworks. It was used to write applications that could look and act just like Apple's preloaded software, so when Apple announced that their SDK was “the same set of tools,” many expected that it would look and feel like the open tool chain. Very few had anticipated the many restrictions they've come to find in the official SDK. While roughly 75% of the two SDKs do overlap, the remaining 25% has shown to be very restrictive, removing the developer's ability to do “the real fun stuff” with their application.

3. The demand was there. The number of slots in the official API program is far smaller than the apparent demand. We published the book, and it sold out immediately, indicating that we were right. We do plan to update the book with information about the official API as soon as the Apple NDA is lifted, but for now, we are eager to fuel the fire, since we believe that the iPhone is one of the most important new platforms in the market today, and one that developers should be exploring as deeply (and as soon) as possible.

See also Jonathan's article on the O'Reilly Network about open API development for the iPhone for more information about the difference between the two APIs, and why developers need to know about both. We're also planning to have a strong open mobile development track at OScon.

明天太平洋时间早上10点oreilly.com有一个免费的Web直播——Jonathan A. Zdziarski，iPhone骇客，也是“iPhone开放应用开发”一书的作者。下面引用这次活动的公告：

Jonathan将演示如何使用iPhone开源工具链来设计能在所有iPhone上运行的第三方软件，既可以在现在的iPhone上运行，也可以在基于官方SDK的下一版本固件的iPhone上运行。他将在运行Leopard的Mac上演示。

将Jonathan介绍给大家的人是Brian Jepson，他是Make杂志Make:Books系列的执行编辑，“Mac　OS X Tiger for Unix Geeks”以及其他一些Geek图书的作者之一，也是一位iPhone骇客。

这是一次向专家学习构建iPhone应用建议的机会，可以直接向专家提问。

参加人数有限，需要现在报名。我们会在Web直播之前发出提醒。

日期：周四，4月3日上午太平洋时间10时（格林威治时间17:00 ）
费用：免费
时间： 30-45分钟
会议链接： oreilly.com/go/webcast-iphone
电话拨入（选择最接近你位置的号码）：
东海岸美国： +1 617 231-0350，PIN 8136507
西海岸美国： +1 213-455-0500，PIN 8136507

很多人会不理解为什么官方SDK已经宣布的情况下O'Reilly还会出版这本针对开源工具链的书。（我也吃惊）我们是在Apple从第一批iPhone骇客那里认识到人们期望比这个电话更多的东西（还发布了开放API）之前就开始这本书了。那为什么不拖住出版进程、按照官方API修改、然后在官方API向业界开放的时候（应该是6月）发布这本书？有三个原因：

1. 我们坚定地认为骇客选择的道路和官方开发人员铺就的、为了安全而丧失很多特点的“自然”道路是不同的。聪明的公司理解这一点，会很关注骇客。（Google Maps就是这一点很好的例证。Google迅速选择如何去为骇客们所做的一切添砖加瓦而不是关掉那些早期的组合服务，结果Google Maps成为地图平台首选。）我们认为无论官方同意与否Apple知道骇客对于iPhone的热情是他们事业和目标的巨大推动。（这一点Cambridge MA的苹果店允许Jonathan在会议上介绍开放iPhone开发就足以证明。）

2. 开放API和官方API有很大一部分是重合的。所以尝试并使用开放工具链会帮助开发人员领先一步。它也比官方工具链更强大，而且会使开发人员继续推着Apple朝有趣的新方向走。Jonathan写道：

有了Apple的SDK，开发人员会按照去年8月发布的非官方的开放API来比较官方API的功能。在构建这个开源iPhone编译器时开发社区提供了很多设备上低层的API。通过像class-dump、nm或者纯粹的“尝试-失败”的办法开发人员可以使用iPhone框架中最广泛的功能。这样就能够写出和Apple预装软件一样的应用，所以当Apple宣称其SDK是“同样一套工具”时很多开发人员希望它和开源工具链一样，很少有人会预见到官方SDK中的很多限制。差不多75%的API是重合的，另外的25%则非常局限，剥夺了开发人员开发“真正有趣的东西”的能力。

3. 这本书有市场需求。官方API远远小于目前的需求。这本书一出版立刻销售一空，这就证明我们是对的。O'Reilly打算一旦Apple保密协议开放就把官方API更新到书里去，而现在则希望推波助澜，我们相信iPhone是目前非常重要的平台之一，开发人员正在极力最大限度地深入探索它。

也可以看看Jonathan在O'Reilly Network上关于iPhone开放API开发的文章，有关于两种API差别的更多信息，以及为什么开发人员需要同时了解它们二者。我们也会在OSCON上针对开放移动设备开发有浓墨重彩。