DZone.com: Using a virtual machine to play with multiple versions of PHP
On DZone.com Giorgio Sironi has a new post talking about a development practice that's becoming more and more popular (rather than the old standby of one development platform for all developers) - using virtual machines as reusable, easily renewable platforms. He talks about the process he went through to set up PHP, including the commands used during the process.
This is an occasion to learn about a virtualization tool which I'm not familiar with, VirtualBox. The goal is to install PHP 5.4, which is not yet a stable release, to play around with new features such as traits without ruining the setup on my primary machine (which runs the super-stable PHP 5.3). Although it may be possible to run them together (I'm not a sysadmin), it's really simpler to install one of them in a virtual machine that can be thrown away if something goes wrong.
Using VirtualBox he describes the process of getting a Ubuntu system up and running including a custom compile of PHP with things like curl, bz2, mbstring and openssl support. With that installed and the Apache packages all set up, it should just be a matter of hitting your localhost's web server. If you're looking for older (or just other) versions of PHP to compile, check out the Historical Releases page on the PHP.net site.