"Heavy-duty computer-science folks tend to get frustrated with scripting languages because they’re not precise," says Rasmus Lerdorf, an engineer at Yahoo and inventor of the PHP language. "But for someone who has a lot of work to do and needs to go home on Friday afternoon, it just works."
Lerdorf, a native of Denmark, started PHP in 1994 to make it easier for novice programmers to quickly pull information from a variety of databases, display it on the Web, and send browsers’ responses back to the server. "Since then, it’s grown like crazy," he says. "It makes it extremely easy to whip something together very quickly."
For one, scripting languages are interpreted by the computer as they run rather than compiled into byte code, which means developers can test chunks of code while they’re writing them. "You can write a few lines, test it, see if you’re on the right track, and do course corrections," says Jeff Barr, a Web-services evangelist at Amazon.com.
Also, since Web browsers don’t distinguish between strings of letters and numbers, PHP takes educated guesses to convert user’s input to integers that back-end data- processing software can understand. With more precise programming languages, developers have to define variables as strings of text or numbers before they assign values to them, which means more advance planning and less brain-dump-style programming.
To be sure, Java, C++, and C# remain the languages of choice for developing systems that have to meet stringent performance standards or serve large numbers of users. PHP "was never meant to be a new, revolutionary language," Lerdorf says.