TIOBE Programming Community Index
Objective-C's rise in popularity seems to come to a halt
Before the summer of 2009, Objective-C was a programming language that was hardly known and used. Thanks to the success of the iPhone and later on the iPad, Objective-C started at that date with an incredible rally to the top. This resulted in two consecutive "TIOBE language of the year" awards in 2011 and 2012. However recently the popularity of Objective-C is not rising any more. For the first time since 2009 it loses a position in the index (from #3 to #4).
The TIOBE Programming Community index is an indicator of the popularity of programming languages. The index is updated once a month. The ratings are based on the number of skilled engineers world-wide, courses and third party vendors. The popular search engines Google, Bing, Yahoo!, Wikipedia, Amazon, YouTube and Baidu are used to calculate the ratings. Observe that the TIOBE index is not about the best programming language or the language in which most lines of code have been written.
The index can be used to check whether your programming skills are still up to date or to make a strategic decision about what programming language should be adopted when starting to build a new software system. The definition of the TIOBE index can be found here.