Howtoforge posted a guide about integrating XCache into PHP5 (Fedora 13/CentOS 5.5 and Apache2)

This guide explains how to integrate XCache into PHP5 on a Fedora 13 or CentOS 5.5 system (with Apache2). From the XCache project page: "XCache is a fast, stable PHP opcode cacher that has been tested and is now running on production servers under high load". It's similar to other PHP opcode cachers, such as eAccelerator and APC.

  Integrating XCache Into PHP5 (Fedora 13/CentOS 5.5 and Apache2)