diff --git a/boto/emr/connection.py b/boto/emr/connection.py
index 1f621ce..4bb72c7 100644
--- a/boto/emr/connection.py
+++ b/boto/emr/connection.py
@@ -138,8 +138,8 @@ def add_jobflow_steps(self, jobflow_id, steps):
         return self.get_object('AddJobFlowSteps', params, RunJobFlowResponse)
 
     def run_jobflow(self, name, log_uri, ec2_keyname=None, availability_zone=None,
-                    master_instance_type='m1.small',
-                    slave_instance_type='m1.small', num_instances=1,
+                    main_instance_type='m1.small',
+                    subordinate_instance_type='m1.small', num_instances=1,
                     action_on_failure='TERMINATE_JOB_FLOW', keep_alive=False,
                     enable_debugging=False,
                     steps=[]):
@@ -154,10 +154,10 @@ def run_jobflow(self, name, log_uri, ec2_keyname=None, availability_zone=None,
         :param ec2_keyname: EC2 key used for the instances
         :type availability_zone: str
         :param availability_zone: EC2 availability zone of the cluster
-        :type master_instance_type: str
-        :param master_instance_type: EC2 instance type of the master
-        :type slave_instance_type: str
-        :param slave_instance_type: EC2 instance type of the slave nodes
+        :type main_instance_type: str
+        :param main_instance_type: EC2 instance type of the main
+        :type subordinate_instance_type: str
+        :param subordinate_instance_type: EC2 instance type of the subordinate nodes
         :type num_instances: int
         :param num_instances: Number of instances in the Hadoop cluster
         :type action_on_failure: str
@@ -180,7 +180,7 @@ def run_jobflow(self, name, log_uri, ec2_keyname=None, availability_zone=None,
 
         # Instance args
         instance_params = self._build_instance_args(ec2_keyname, availability_zone,
-                                                    master_instance_type, slave_instance_type,
+                                                    main_instance_type, subordinate_instance_type,
                                                     num_instances, keep_alive)
         params.update(instance_params)
 
@@ -227,11 +227,11 @@ def _build_step_list(self, steps):
                 params['Steps.memeber.%s.%s' % (i+1, key)] = value
         return params
 
-    def _build_instance_args(self, ec2_keyname, availability_zone, master_instance_type,
-                             slave_instance_type, num_instances, keep_alive):
+    def _build_instance_args(self, ec2_keyname, availability_zone, main_instance_type,
+                             subordinate_instance_type, num_instances, keep_alive):
         params = {
-            'Instances.MasterInstanceType' : master_instance_type,
-            'Instances.SlaveInstanceType' : slave_instance_type,
+            'Instances.MainInstanceType' : main_instance_type,
+            'Instances.SubordinateInstanceType' : subordinate_instance_type,
             'Instances.InstanceCount' : num_instances,
             'Instances.KeepJobFlowAliveWhenNoSteps' : str(keep_alive).lower()
         }
diff --git a/boto/rds/__init__.py b/boto/rds/__init__.py
index 423365b..8e82ca0 100644
--- a/boto/rds/__init__.py
+++ b/boto/rds/__init__.py
@@ -80,7 +80,7 @@ def get_all_dbinstances(self, instance_id=None, max_records=None,
         return self.get_list('DescribeDBInstances', params, [('DBInstance', DBInstance)])
 
     def create_dbinstance(self, id, allocated_storage, instance_class,
-                          master_username, master_password, port=3306,
+                          main_username, main_password, port=3306,
                           engine='MySQL5.1', db_name=None, param_group=None,
                           security_groups=None, availability_zone=None,
                           preferred_maintenance_window=None,
@@ -109,13 +109,13 @@ def create_dbinstance(self, id, allocated_storage, instance_class,
         :type engine: str
         :param engine: Name of database engine. Must be MySQL5.1 for now.
 
-        :type master_username: str
-        :param master_username: Name of master user for the DBInstance.
+        :type main_username: str
+        :param main_username: Name of main user for the DBInstance.
                                 Must be 1-15 alphanumeric characters, first must be
                                 a letter.
 
-        :type master_password: str
-        :param master_password: Password of master user for the DBInstance.
+        :type main_password: str
+        :param main_password: Password of main user for the DBInstance.
                                 Must be 4-16 alphanumeric characters.
 
         :type port: int
@@ -166,8 +166,8 @@ def create_dbinstance(self, id, allocated_storage, instance_class,
                   'AllocatedStorage' : allocated_storage,
                   'DBInstanceClass' : instance_class,
                   'Engine' : engine,
-                  'MasterUsername' : master_username,
-                  'MasterUserPassword' : master_password}
+                  'MainUsername' : main_username,
+                  'MainUserPassword' : main_password}
         if port:
             params['Port'] = port
         if db_name:
@@ -197,7 +197,7 @@ def create_dbinstance(self, id, allocated_storage, instance_class,
 
     def modify_dbinstance(self, id, param_group=None, security_groups=None,
                           preferred_maintenance_window=None,
-                          master_password=None, allocated_storage=None,
+                          main_password=None, allocated_storage=None,
                           instance_class=None,
                           backup_retention_period=None,
                           preferred_backup_window=None,
@@ -218,8 +218,8 @@ def modify_dbinstance(self, id, param_group=None, security_groups=None,
                                              which maintenance can occur.
                                              Default is Sun:05:00-Sun:09:00
 
-        :type master_password: str
-        :param master_password: Password of master user for the DBInstance.
+        :type main_password: str
+        :param main_password: Password of main user for the DBInstance.
                                 Must be 4-15 alphanumeric characters.
 
         :type allocated_storage: int
@@ -270,8 +270,8 @@ def modify_dbinstance(self, id, param_group=None, security_groups=None,
             self.build_list_params(params, l, 'DBSecurityGroups.member')
         if preferred_maintenance_window:
             params['PreferredMaintenanceWindow'] = preferred_maintenance_window
-        if master_password:
-            params['MasterUserPassword'] = master_password
+        if main_password:
+            params['MainUserPassword'] = main_password
         if allocated_storage:
             params['AllocatedStorage'] = allocated_storage
         if instance_class:
diff --git a/boto/rds/dbinstance.py b/boto/rds/dbinstance.py
index b06dd9e..51e0510 100644
--- a/boto/rds/dbinstance.py
+++ b/boto/rds/dbinstance.py
@@ -36,7 +36,7 @@ def __init__(self, connection=None, id=None):
         self.allocated_storage = None
         self.endpoint = None
         self.instance_class = None
-        self.master_username = None
+        self.main_username = None
         self.parameter_group = None
         self.security_group = None
         self.availability_zone = None
@@ -78,8 +78,8 @@ def endElement(self, name, value, connection):
             self.allocated_storage = int(value)
         elif name == 'DBInstanceClass':
             self.instance_class = value
-        elif name == 'MasterUsername':
-            self.master_username = value
+        elif name == 'MainUsername':
+            self.main_username = value
         elif name == 'Port':
             if self._in_endpoint:
                 self._port = int(value)
diff --git a/boto/rds/dbsnapshot.py b/boto/rds/dbsnapshot.py
index 78d0230..166501e 100644
--- a/boto/rds/dbsnapshot.py
+++ b/boto/rds/dbsnapshot.py
@@ -33,7 +33,7 @@ def __init__(self, connection=None, id=None):
         self.port = None
         self.status = None
         self.availability_zone = None
-        self.master_username = None
+        self.main_username = None
         self.allocated_storage = None
         self.instance_id = None
         self.availability_zone = None
@@ -61,8 +61,8 @@ def endElement(self, name, value, connection):
             self.status = value
         elif name == 'AvailabilityZone':
             self.availability_zone = value
-        elif name == 'MasterUsername':
-            self.master_username = value
+        elif name == 'MainUsername':
+            self.main_username = value
         elif name == 'AllocatedStorage':
             self.allocated_storage = int(value)
         elif name == 'SnapshotTime':
diff --git a/docs/source/conf.py b/docs/source/conf.py
index 57b1221..4fba7d4 100644
--- a/docs/source/conf.py
+++ b/docs/source/conf.py
@@ -5,7 +5,7 @@
 extensions = ['sphinx.ext.autodoc', 'sphinx.ext.intersphinx', 'sphinx.ext.todo']
 templates_path = ['_templates']
 source_suffix = '.rst'
-master_doc = 'index'
+main_doc = 'index'
 project = u'boto'
 copyright = u'2009,2010, Mitch Garnaat'
 version = '1.9'