The TIOBE Programming Community index gives an indication of the popularity of programming languages. The index is updated once a month. The ratings are based on the world-wide availability of skilled engineers, courses and third party vendors. The popular search engines Google, MSN, and Yahoo! are used to calculate the ratings. Observe that the TPC index is not about the best programming language or the language in which most lines of code have been written.
Where PHP stands currently (In the month of october)
Position (Oct 2006): 4
Position (Oct 2005): 4
Ratings (Oct 2006): 9.863%
Delta (Oct 2005): +0.19%
The status of A means it is a mainstream programming language language
The full list can be found here: http://www.tiobe.com/tpci.htm