ZendFramework integration with other frameworks

[alkafee]

I want to make this question a guide for those interested in ZendFramework integration with other libraries/frameworks. Searching over StackOverflow doesn't give a broad view on the subject.The question is: which libraries/frameworks do you use in your current ZF-based project? what are the best practices for ZF-based project architecture?I don't mean any components that are already a part of ZF. Please give a description of aditional frameworks you have integrated (like RuckUsing, Smarty, or Doctrine). It also applies to any GUI frameworks (perhaps you use a CSS framework), as well as JS frameworks (not just jQuery or prototype, but rather some advanced structures).The main requirement: it has to be a ZendFramework project.Additional bonus will be given to answers that describe performance optimization.UPDATEEvery answer as informative as @BryanM's will be considered for additional bounty award.