Halp! Requested. libpng.s0.3? HUH?Quakeworld

[Hellofriends]

Hello good friends!
I am on Ubuntu!
I am trying to run ftequakeworld gl while in quake directory by typing ./fteqw.gl
it gives me this error:
./fteqw.gl: error while loading shared libraries: libpng.so.3: cannot open shared object file: No such file or directory

O_O What wickedness is this?
Any help would be much appreciated thank you very much!

[Hellofriends]

Is libpng.so.3 a file a I need to download? any suggestions?

[Hellofriends]

Ok I installed something from Ubuntu and now it boots! YAY!
Only NO SOUND :((
Please help me gentlemen!

I get this error:(I think this is the error that is the problem)

Initing OSS sound device /dev/dsp
/dev/dsp: Broken pipe

Any ideas?
UPDATE:
Alsa does not appear to be installed or compatable
Initing OSS sound device /dev/dsp
/dev/dsp: Broken pipe
OSS: Could not toggle.

Alsa does not appear to be installed or compatable? must be audio yes?