Despite being much criticized, PHP is still one of the predominate programming languages for web development. Initially released in 1995 as Personal Home Page Tools, PHP forms one of the pillars of the popular LAMP platform stack.
Microsoft initially saw PHP as a competitor and released the rival product ASP, or Active Server Pages, in December of 1996. Known today as "Classic ASP", it is still shipped with Internet Information Server and is widely available. However, unlike PHP it is no longer under active development and no new versions are expected.
One reason PHP is popular is that it is seen as a response to the complexities of platforms like ASP.NET and J2EE. While other platforms target enterprise developers and strive for a degree of purity, PHP is thought of as very pragmatic language that has grown around its developers' needs. Of course there are others that see it as a hodge-podge of inconsistent features.
Whatever your view of PHP, there is no denying that it will be with us for a long time. It is too popular to simply fade away and active development by the PHP Group helps to attract new projects.
Recently Microsoft has acknowledged that PHP is not a competitor, but rather just another product. With the real competition being Linux, Microsoft has started courting PHP developers with deep support for IIS 7. In a Channel 9 Webcast, Ryan Dunn talks about installing PHP on IIS and using IIS 7's integrated pipeline from a PHP application to support form's authentication.
Another long overdue product is a SQL Server driver for PHP. Currently the database engine of choice for PHP developers is MySQL. Even though Microsoft's SQL Server Express is comparable to MySQL and free, it does not currently have a native driver for PHP. Microsoft has released a preview of the SQL Server driver for PHP.
