Facebook beat Twitter as the top Social API, while Spotify came ahead of Echo Nest as the main Music API. Unity was the top Game Engine.
Devpost's numbers are based on adding up the project tags from a sample of 13,281 student hackers from 160 student hackathons and their Devpost portfolios. The survey covered 9,898 projects in a huge array of subjects. While most of the hackathons were held in North America, some were held in the UK, Poland, Singapore and other countries.
Some scores are obviously influenced by sponsorship and support operations. For example, Azure trumped Heroku and Amazon Web Services partly because Microsoft is a strong supporter of student hackathons. MongoDB probably benefited from participating in a lot of hackathons as well.
Companies get involved with student hackathons partly to encourage such use, of course, as well as to identify potential hires and for the generally good publicity. However, Devpost's numbers identify the technologies used, not the ones the students actually prefer, or are the most powerful. In hackathons, the most important feature is the ability to generate code as quickly as possible.
In the projects based on mobile technologies, Android was the most popular platform (38.2 percent), followed by Apple's iOS (22.7 percent) and Windows Phone (4.9 percent). In this case, the ranking is probably influenced by cost as well.
In projects that used hardware, Arduino topped the list, followed by Myo, Pebble, Leap Motion, Oculus Rift, Raspberry Pi, Intel Edison, Kinect, Particle (Spark) and Google Cardboard. Students seem to be interested in VR (Virtual Reality). However, Devpost says: "During the spring semester, Pebble, Oculus, Leap Motion, Intel Edison, Raspberry Pi, Muse, and Meta grew in popularity, likely due to company sponsorship."
Not all the students' tags were technology. Devpost comments that "Coffee and Red Bull were dead even, but pizza beat out guacamole. There was more blood and sweat in the Spring than in the Fall, but tears were steady throughout the academic year."
There's a very good reason to visit Devpost's one-page Student Hacker Report: Technology & API rankings for the 2014-2015 academic year. Clicking on each technology takes you to the Devpost/ChallengePost website where you can read about the student projects, many of which include a short YouTube video.
If you want to know what students are doing with, for example, Intel Edison, you can click the link and find 106 examples. You never know, some projects might spark new ideas.