What Third-Party Library Do You Integrate with Yii?

I’m looking ahead to writing Chapter 20, “Working with Third-Party Libraries,” of “The Yii Book” (I’m currently writing Chapter 19), and was wondering what people wanted me to specifically demonstrate. Originally, I had intended to use the Zend Framework as my example. I like how ZF components can be easily used on their own, and I’d frequently used ZF with my own Yii projects.�Lately, I’ve been thinking about using Symfony in the chapter. I’ve not touched Symfony yet myself, but have heard good things.�Of course, the examples don’t have to use frameworks; they could use any type of library.

So as I’m gearing up to write that chapter, I was wondering what third-party library you integrate with Yii? Or, what third-party library would you like to integrate with Yii? Or, what third-party library would you like to see me integrate with Yii?

Any and all suggestions and feedback are most welcome. Thanks!