Type 'netbeans --help' to find out.

Command-line switches can be entered using GNU style, meaning they are preceded with two hyphens rather than one (e.g.: --help) or single-letter switches (e.g.: -h). JVM flags are entered using only one hyphen as in -Jjvm_flag, for example.

You can use the following command-line switches:

-h, --help

Print descriptions of common startup parameters.

--jdkhome jdk_home_dir

Use the specified version of the JDK instead of the default JDK. More info.

--cp:p classpath

Prepend the specified classpath to the IDE's classpath. This option is generally not recommended for any purpose.

--cp:a classpath

Append the specified classpath to the IDE's classpath.

-Jjvm_flag

Pass the specified flag directly to the JVM.

--laf ui_class_name

Use a given class as the IDE's look and feel. More info.

--fontsize size

Use a given size in points as the basic font size for the IDE user interface. More info.

--locale language[:country[:variant]]

Use the specified locale.

--userdir userdir

Explicitly specify the userdir, which is the location in which user settings are stored. More info.

--open file, --open file:line

Opens the file in the IDE's source editor at the specified line.

Source: NetBeans User FAQ