What does Public Domain / GPL / OFL mean? Can this font be used in a commercial publication? Is it free?

Thanks

Yes

Some stuffs to read :
Public domain : http://en.wikipedia.org/wiki/Public_domain
The GPL License : http://en.wikipedia.org/wiki/GNU_General_Public_License
The OFL License : http://en.wikipedia.org/wiki/SIL_Open_Font_License