I'm ready to start adding sound effects to my game, so I've been looking at audio libraries. My requirements are that the library be cross-platform, free for commercial use, and under a friendly license (not GPL/LGPL).

The three main options I see right now are Fmod, OpenAL, and PortAudio. However, each one has both pros and cons to them.

Everyone knows Fmod, its used in tons of game, has all sorts of tools to make it easy. There is a free version of it, but I eventually plan to sell my game, so I can't go with a free license. However, I also can't afford to spend $500 on an audio library.

OpenAL seemed to be the next logical choice. Not so simple, not as much documentation, but free to use. However, in looking into it again recently, it appears that development has gone proprietary, and only the old 1.1 version is still freely available. Choosing an old abandoned library to learn to use for the first time doesn't sound like all that great an idea.

And then there is PortAudio. Also free, and very much in active development. However, it is also extremely low level, more targeted towards professional audio applications than games. It seems to be little more than an abstraction of the audio hardware, so everything on top of that (file decoding, volume adjustment, effects, etc.) I would have to do myself (or find another library to sit on top of it). On one hand, it could be really useful when it comes to generating abstract sounds rather than just playing pre-recorded files (something I plan to do eventually to some degree), but for everything else it sounds like it will be a huge undertaking.

None of them seem to be ideal, but I haven't had much luck finding another audio library that fits my requirements. Are there other options that people know of? Something I'm overlooking?

Admittedly not for very strong reasons. Mostly because it prevents me from static linking the library. I don't know if there are other restrictions, the LGPL license is rather cryptic.

I assume SDL_mixer can't be used independently from the rest of SDL? I'm using GLFW for display and input, I never cared much for SDL.

Sorry about the thread-gravedigging.

I don't really know much about sound libraries, but came across this as I'm looking for something similar.
I stumbled upon a thread on StackOverflow pointing me to SFML.
That seems to be popular, and the license is very open: http://www.sfml-dev.org/license.php

As a follow up, I used PortAudio for a while, and got everything up and running with Ogg playback. It worked well, sounded good, but had non-constant latency that I could never fully get rid of.

In the end, I scrapped it and decided to just use each platform's native audio API (XAudio2 on Windows, PulseAudio on Linux) and decode Ogg myself using stb_vorbis, rather than try to find a single cross-platform library to do it all for me. Latency is gone, and I have the platform code abstracted behind a common interface, so it meets my requirements well enough for now.