An introduction to PHP, covering topics from history of the platform and personalities involved, to strengths/weaknesses of the language and how to best use it.
Available under the Creative Commons Attribution Share-Alike Non-Commercial Unported 3.0 license.
18. Available on Linux, Unix, Windows , Mac OS X, AS/400, Novell NetWare, OS/2, RISC OS, SGI IRIX 6.5.x, Solaris (SPARC, INTEL), Solaris OpenCSW packages