> What makes mp3 still worth considering?

A lot of people (including myself) won't re-encode their existing music collections into another lossy format to avoid degradation in sound quality.

Also, as much as it sucks these days, a lot of people (including myself) are still in the Apple ecosystem (formerly iTunes, now Music.app). For these people, mp3 seems to be the best compressed format that's compatible with the rest of the world.

I use MP3 a lot myself, so I built this tool around it.

Cjam is designed in a way that makes it easy to adapt to other small, lossy formats as well, so it has potential to go beyond MP3 in the future.

You're right, but mp3 is still even more widely supported. It is also good enough, most people can't tell the difference between original files and around 128kbps ABR mp3 files, let alone higher bitrates. And there are huge personal libraries of mp3 files out there that are not going away.

That said, I don't see the use of this tool. It's a proprietary tool that does basic things for which free tools (in every sense of the word) have existed for a long time now.

> BTW is mp3 still relevant now? It seems that AAC, Opus, and Vorbis are all clearly superior, and widely supported. What makes mp3 still worth considering?

It is incredibly relevant. MP3 is the baseline standard for lossy compressed audio. If you have an MP3, you can play it and convert it anywhere. There are definitely benefits of AAC and others, but they are not great enough to forgo the universality of the MP3 format when all you want is 2 channel 16 bit 44.1khz audio.