One sure way to improve performance is to cache the non-dynamic data of any application. We did this to improve the overall performance of The Virtualization Practice website. However, there are many places within the stack to improve overall performance by caching, and this got me to thinking of all the different types. At the last Austin VMUG, there were at least three vendors selling caching solutions that were designed to improve overall performance by as little as 2x to upwards of 50x improvements. That is quite a lot of improvement in application performance. Where do all these caching products fit into the stack?