Command Line Options

All command line option related information can be found here.

Summary of command line options:
-auroraaddress -version -w -launch -battlenetaddress -battlenetmatchmakingaddress -test -perftestfilter -perftestwaittime -perftestsampletime -perftestdumpfreq -perftestformat

-auroraaddress
Tells client to connect a specific ip:port.

-w
Runs the game in windowed mode.

-launch
Runs the game without starting the launcher (agent).

Example:
"Diablo III.exe" -w -launch -auroraaddress 127.0.0.1:1345

My video card is not supported?
Override by setting HardwareClass to "4" in Documents\Diablo III\3dprefs.txt. This will override the check and force texture loading - quality will vary, of course.