Objective-C, best known as the programming language used for building applications to run on Apple's popular iPad and iPhone devices, is beginning to level off in popularity, one monthly assessment of languages reports.

The Tiobe Programming Community Index for April has Objective-C slipping a spot, dropping to fourth place and displaced by C++. The index gauges language popularity based on the number of skilled engineers worldwide, courses, and third-party vendors pertinent to each language, with popular search engines such as Google and Yahoo, as well as other sites used to make the assessment.

This month's index had Objective-C coming up in 9.60 percent of searches, which was down from 10.23 percent in April. The language is still up from one year ago, when it showed up in just 8.24 percent of searches.

An official at Tiobe ties Objective-C's fortunes to what he believes is a decline for iPad and iPhone, while Samsung's profile in the Android space is rising.

"Yes, if you look at the long-term trend, then Objective-C is still rising, but the short-term trend doesn't look good," said Paul Jansen, managing director at Tiobe. "The main reason is that the iPhone and iPad are losing popularity and thus their programming language Objective-C. On the other hand, Samsung is in the lead now in the mobile market, resulting in an expected rise of the Android language Java in the near future."

For the time being, Java slipped back to second place in the index after recovering the lead from the C language in February. Java had dropped to second place a year ago. But C and Java are in a virtual dead heat this month, with C scoring a 17.862 percent rating while Java was at 17.681 percent.

"The fact that C swapped places with Java is indeed a bit coincidental. It can just be the other way around again next month," said Jansen.

C++ scored a 9.714 percent rating. Following Objective-C, the index has C# in fifth place (6.15 percent), followed by PHP (5.43 percent), Visual Basic (4.70 percent), Python (4.44 percent), Perl (2.34 percent), and Ruby (1.97 percent).

This month's rival Pypl Popularity of Programming Language index, which analyses how often language tutorials are searched on Google, has Java in the top spot at 26.7 percent, followed by PHP (14.3 percent), C# (10.1 percent), Python (10 percent), and C++ (9.2 percent). Rounding out the top 10 languages are C (8.1 percent), JavaScript (8 percent), Objective-C (5.6 percent), Visual Basic (3.2 percent), and Ruby (2.8 percent).