先看一段话

Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

看到这段话眼熟吧，不眼熟说明你控件掌握的不好。

Lorem ipsum是指一篇常用于排版设计领域的拉丁文文章，主要的目的为测试文章或文字在不同字型、版型下看起来的效果。中文的类似用法则称为乱数假文。

Lorem ipsum从15世纪开始就被广泛地使用在西方的印刷、设计领域中，在电脑排版盛行之后，这段被传统印刷产业使用几百年的无意义文字又再度流行。由于这段文字以“Lorem ipsum”起头，并且常被用于标题的测试中，所以一般称为Lorem ipsum，简称为Lipsum。

原先大家以为这段拉丁文只是没有意义的组合，目的是让阅读者不要被文章内容所影响，而只专注于观察字型或版型，并借此填满空间。但根据美国拉丁学者Richard McClintock的研究，Lorem ipsum原来起源于西赛罗《善恶之尽》（De finibus bonorum et malorum）第一章（Liber Primus）的32、33两节：

（粗体字中译：寻之欲之，乃因其苦，但事实中有痛苦可以带来巨大的…以一小例子为例，有没有人…剧烈运动，可以为他带来好处？…）

为了减少Lorem ipsum的可读性，并且让字母频率与现代英语接近，所以有些版本中部分字母被K、W、Z等拉丁文中没有的字母替换，或是加入zzril、takimata等字。除了原始的Lorem ipsum版本外，网上还有不同长度和不同语言的版本可供使用。

说白了就是Hello world.

其他各领域的Hello world:

附上英文版翻译:

But I must explain to you how all this mistaken idea of denouncing of a pleasure and praising pain was born and I will give you a complete account of the system, and expound the actual teachings of the great explorer of the truth,
 the master-builder of human happiness. No one rejects, dislikes, or avoids pleasure itself, because it is pleasure, but because those who do not know how to pursue pleasure rationally encounter consequences that are extremely painful.
 Nor again is there anyone who loves or pursues or desires to obtain pain of itself, because it is pain, but occasionally circumstances occur in which toil and pain can procure him some great pleasure. To take a trivial example, 
which of us ever undertakes laborious physical exercise, except to obtain some advantage from it? But who has any right to find fault with a man who chooses to enjoy a pleasure that has no annoying consequences, 
or one who avoids a pain that produces no resultant pleasure? On the other hand, we denounce with righteous indignation and dislike men who are so beguiled and demoralized by the charms of pleasure of the moment, 
so blinded by desire, that they cannot foresee the pain and trouble that are bound to ensue; and equal blame belongs to those who fail in their duty through weakness of will, 
which is the same as saying through shrinking from toil and pain. These cases are perfectly simple and easy to distinguish. In a free hour, 
when our power of choice is untrammeled and when nothing prevents our being able to do what we like best, every pleasure is to be welcomed and every pain avoided. 
But in certain circumstances and owing to the claims of duty or the obligations of business it will frequently occur that pleasures have to be repudiated and annoyances accepted. 
The wise man therefore always holds in these matters to this principle of selection: he rejects pleasures to secure other greater pleasures, or else he endures pains to avoid worse pains.

参考文档：
http://zh.wikipedia.org/wiki/Lorem_ipsum
http://en.allexperts.com/q/Ancient-Languages-2210/2009/6/quotes-meaning-LATIN.htm
　　　　　　

what is Lorem ipsum?