When I choose the backend code for NewsWave several years ago I went with PHP after listening Marco’s recommending it due to its reliability and stability. After several years I can confirm.
Apparently a lot of other fellow developers think the same looking at the latest data from Ars Technica.
If you’re planning a new project, I can’t recommend PHP enough for server-side. It may not be sexy, it may not be cool but it consistently delivers without a hitch.