Where is the mess? Everywhere: sound, video, embedding, etc.

> Sound. How well OSS emulation is working today? Oh, right, OSS API was a mess and so it can not be adequately supported. Now everyone must rewrite everything for ALSA... or may be GStreamer... or may be PulseAudio...
This is downright bullshit. There's OSS emulation in ALSA and it works most of the time. PulseAudio has padsp for OSS-only applications and an ALSA plugin for ALSA-only applications.

> Video. There are just two interfaces: V4L and V4L2. So if I don't need the features I can safely use V4L, right? Oh, no backward compatibility...
Again, this is just bullshit. V4L2 drivers do include a compatibility mode for V4L applications.

> Widgets. Can I embed Qt widget in a GTK program? No? Why No? Ok. At least GTK widgets are usable in Qt (not so long ago this was impossible too).
I agree that having two GUI toolkits is unfortunate, but it has _nothing_at_all_ to do with backward compatibility.

> 1. APIv1 is introduced.
> 2. APIv2 is introduced some years later. Now you must support both APIv1 and APIv2. Because they don't play well on the same system and you never know when particular distributions will switch from APIv1 to APIv2.
Right, except that you failed to provide even *one* example. I have gtk2 and gtk3 applications running side-by-side right now. I've run a Qt3 application (Xilinx ISE) just a few months ago.

So please, just stop making up random bullshit here.