If you've ever listened to digital music, you've probably did so using an MP3 file. The MP3 is a ubiquitous staple of digital audio for decades and is one of the most common ways people listen to music. Now the institute that initially developed the MP3 has terminated its licensing fees, meaning the MP3 is now free.

In 1988, a group of engineers were faced with a problem: audio files were too large. A hit single might take up several kilobytes of storage space, which was a lot in 1988. The rise of portable digital audio players earlier in the decade meant people were constantly looking for a way to fit more files into less space.

The engineers at the Fraunhofer Institute hit on the solution: a type of compression algorithm that could make audio files smaller without losing sound quality. Their algorithm identifies parts of the audio that are beyond the range of normal human hearing and removes those parts. The result is an efficient algorithm that produces much smaller audio files though with some loss in quality in the process.

This algorithm became the MP3 file format. The compression algorithm allowed music lovers to store tens of thousands of songs on devices that previously could only hold a few hundred. People built and maintained large personal music libraries that would have required entire rooms to house during the vinyl era.

But the MP3 was not free for anyone to use, however. In order to listen to MP3 files, you had to have a program that could play them. Fraunhofer had patented the encoding and decoding algorithms so any software that wanted to support MP3 formats had to pay Fraunhofer a licensing fee.

But those patents were filed decades ago, and after declining in value in the new age of streaming, the last of them expired this year. Now, anyone can use them, meaning the MP3 is more "alive" than ever before.

But what happens next? The MP3 could become even more common than it already is, like the GIF did when its patents expired in 2003, though it's also likely to fade into obscurity due to the lack of support and the availability of better formats like Advanced Audio Coding (AAC). But whatever happens to the MP3 from here on, it's already completely changed the way we listen to music.