Question

Is there any way I can start OpenGL in software emulation mode, like DirectX where there is reference rendering option?

Answer 1

if you are trying to just test your existing software there are a bunch of tricks… like:
http://www.opengl.org/discussion_boards/ubbthreads.php?ubb=showflat&Number=148011

if you are writing software and have the ability to specify the render… then in windows:

from: http://www.opengl.org/resources/faq/technical/mswindows.htm

To force software rendering from your application, choose a pixel
format that is not hardware accelerated. To do this, you can not use
ChoosePixelFormat(), which always selects a hardware accelerated pixel
format when one is available. Instead, use DescribePixelFormat() to
iterate through the list of available pixel formats. Any format with
the PFD_GENERIC_FORMAT attribute bit set will not be hardware
accelerated.

for linux or mac… I would have to look through real books… let me know if you are on linux/Mac