Gennady Feldman, in light of some of the recent talk about enhancing the performance of your PHP applications, has written up this new post comparing two of the more favored software packages - APC and Eaccelerator.
Some websites use other technologies like Java and face the exact same problems. There are different variables involved here and the most common one is database. So I thought i would post a couple of articles related to performance and tuning.
This this post of the series focuses on the first of the two - APC - and talks about places it's used and includes some general performance recommendations. These include "Don't try to throw everything at your poor database" and the importance of XDebug.