Android：什么是Holo？
Martin Brinkmann on May 6, 2013 in Google Android 3 【Translated By KillerLegend】
当你在Google Play商店上浏览新的应用或者上介绍Android应用的网站时，你会在术语Holo上打住，犹豫不决。很奇妙的是，这经常发生。有时候，应用程序把Holo添加到它们的名字中去，有时候，在描述应用程序或者应用程序的功能时也用到Holo。
Holo或者Holo主题是一种专为Android应用程序而生的的标准主题。在Android 3.0 蜂巢大会上首次被引进。Google为了能够通过所有的制造商提供给用户统一的体验，要求制造商在android4.0或者更高的版本中包含未经修改的Holo主题，这样他们才可以在他们的设备上整合android市场。制造商仍然可以在他们的设备上装载自定义的主题。
就Holo而言，可以很负责的说，大部分Android4.0或者更高版本的设备中都内置有Holo主题，这样可以便于应用程序充分利用它们的资源。Holo的根本目标是减少（直到消除）各式各样的系统主题。
如果你是一个开发者，你或许已经注意到，你确实只接触过三种不同的Holo主题：Holo Light, Holo Dark and Holo Light with dark action bars。这里有三幅屏幕截图展示了Holo样式以及各种主题之间的不同之处。从左至右依次是：Holo Light, Holo Dark and Holo Light with dark action bars
如果你将Holo设计与以前的Android应用程序设计比较，你会发现Holo已经取得了一个很大的进展。但是开发者仍然可以自己的设计，以使他们的应用程序不需要看起来和这儿的一模一样。
这并不意味着运行着低于Android3.0系统的设备将不能够从Holo设计获取好处。恰恰相反的是，设计者可以在任何地方使用资源，风格或者像Holo主题的东西。
=================================================================下面是英文原文
Android: What does Holo mean?
When you are browsing the Google Play store for new apps, or reading websites that review Android apps, you will eventually stumble upon the term Holo. Chance is, this will happen frequently. Sometimes, applications have Holo added to their name, at other times, it is listed in the description of the app or as one of its features.
Holo, or Holo theme, is a standard theme for Android apps that Google first introduced with Android 3.0 Honeycomb. The company requires manufacturers to include the unmodified Holo theme in Android 4.0 or higher devices if they want to integrate Android Market on their device. Manufacturers can still ship their devices with their own custom themes to provide users with a unified experience across all devices by that manufacturer.
As far as Holo is concerned it is fair to say that the majority of Android 4.0 or higher devices have the themes built-in so that apps can make use of their resources. The basic idea behind Holo was to reduce (virtually eliminate) the design variance in regards to system themes.
If you are a developer, you have noticed that you do have access to three different Holo themes: Holo Light, Holo Dark and Holo Light with dark action bars. Here are three screenshots that showcase how these themes look like and differ from one another.
If you compare the Holo design to the design of previous Android apps you will notice that it has come a long way since then. Developers can still create their own visual designs so that their apps do not need to look like the apps displayed here at all.
That does not mean that devices running a lower version than Android 3.0 cannot benefit from Holo designed apps as well. Designers can use the resources and styles, or use something like Holo Everywhere instead.