V$SYSTEM_PARAMETER

Columns
   ___________________________
 
   NUM
   NAME
   DESCRIPTION
   TYPE
   VALUE
   ISADJUSTED
   ISMODIFIED
   ISSYS_MODIFIABLE
   ISSES_MODIFIABLE
   ISDEFAULT

Related Views:

V$NLS_PARAMETERS 
V$NLS_VALID_VALUES 
V$PARAMETER 
V$SYSTEM_PARAMETER2