The annual TIOBE Programming Community Index measures the relative popularity of different programming languages used in software development relative to the previous year. What I find most interesting from their results is not the overall rankings but rather the changes since 2004. From that perspective Java and C# are leading the pack significent growth while C and C++ are falling behind.
Since Tiobe base their rankings on search engine results then it follows that any language that has not grown should still see an index increasae since, as any blogger knows, the longer you exist on the web the larger footprint. It would be interesting if Tiobe baselined their rankings against a language neutral rating for a term like "Programmng Language" ( although scripting language fans might object )
The 2005 index shown below ( ref: http://www.tiobe.com ) shows Java in the lead with a 22% rating, C with 19% and C++ with 11%. PHP and VB came in at 9%, Perl at 7% and C# at 3.5%. Ruby, it's worth mentioning came in at 0.3%.