PHP and Slots in Gentoo
I had a gut-feeling using slots to quickly switch between different versions of PHP in Gentoo would be straightforward and it was. The only piece of the puzzle that eluded me for a while, in the end, was working out how to tell portage to install a specific version. This is acheieved with an equals sign. As such: (Assuming in this instance 5.2 is already installed.)