diff --git a/docs/pyboard/tutorial/lcd_skin.rst b/docs/pyboard/tutorial/lcd_skin.rst
index 4df0041607..9d0ff473e2 100644
--- a/docs/pyboard/tutorial/lcd_skin.rst
+++ b/docs/pyboard/tutorial/lcd_skin.rst
@@ -29,7 +29,7 @@ Make sure the LCD skin is attached to the pyboard as pictured at the top of this
     >>> import pyb
     >>> lcd = pyb.LCD('X')
     >>> lcd.light(True)
-    >>> lcd.write('Hello uPy!\n')
+    >>> lcd.write('Hello MPy!\n')
 
 You can make a simple animation using the code::
 
@@ -38,7 +38,7 @@ You can make a simple animation using the code::
     lcd.light(True)
     for x in range(-80, 128):
         lcd.fill(0)
-        lcd.text('Hello uPy!', x, 10, 1)
+        lcd.text('Hello MPy!', x, 10, 1)
         lcd.show()
         pyb.delay(25)
 
diff --git a/docs/reference/asm_thumb2_index.rst b/docs/reference/asm_thumb2_index.rst
index ccf0201489..97b3a8687e 100644
--- a/docs/reference/asm_thumb2_index.rst
+++ b/docs/reference/asm_thumb2_index.rst
@@ -63,7 +63,7 @@ References
 -  :ref:`Assembler Tutorial <pyboard_tutorial_assembler>`
 -  `Wiki hints and tips
    <http://wiki.micropython.org/platforms/boards/pyboard/assembler>`__
--  `uPy Inline Assembler source-code,
+-  `MicroPython Inline Assembler source-code,
    emitinlinethumb.c <https://github.com/micropython/micropython/blob/master/py/emitinlinethumb.c>`__
 -  `ARM Thumb2 Instruction Set Quick Reference
    Card <http://infocenter.arm.com/help/topic/com.arm.doc.qrc0001l/QRC0001_UAL.pdf>`__
diff --git a/extmod/asyncio/core.py b/extmod/asyncio/core.py
index 5d46b4b80e..7b70b43bce 100644
--- a/extmod/asyncio/core.py
+++ b/extmod/asyncio/core.py
@@ -50,7 +50,7 @@ class SingletonGenerator:
             raise self.exc
 
 
-# Pause task execution for the given time (integer in milliseconds, uPy extension)
+# Pause task execution for the given time (integer in milliseconds, MicroPython extension)
 # Use a SingletonGenerator to do it without allocating on the heap
 def sleep_ms(t, sgen=SingletonGenerator()):
     assert sgen.state is None
diff --git a/extmod/modtls_mbedtls.c b/extmod/modtls_mbedtls.c
index 5863425732..e2f7254f79 100644
--- a/extmod/modtls_mbedtls.c
+++ b/extmod/modtls_mbedtls.c
@@ -304,7 +304,7 @@ static mp_obj_t ssl_context_make_new(const mp_obj_type_t *type_in, size_t n_args
     psa_crypto_init();
     #endif
 
-    const byte seed[] = "upy";
+    const byte seed[] = "mpy";
     int ret = mbedtls_ctr_drbg_seed(&self->ctr_drbg, mbedtls_entropy_func, &self->entropy, seed, sizeof(seed));
     if (ret != 0) {
         mbedtls_raise_error(ret);
diff --git a/extmod/vfs.c b/extmod/vfs.c
index aebf5ed295..d2a7af5de0 100644
--- a/extmod/vfs.c
+++ b/extmod/vfs.c
@@ -96,7 +96,7 @@ mp_vfs_mount_t *mp_vfs_lookup_path(const char *path, const char **path_out) {
     return MP_STATE_VM(vfs_cur);
 }
 
-// Version of mp_vfs_lookup_path that takes and returns uPy string objects.
+// Version of mp_vfs_lookup_path that takes and returns MicroPython string objects.
 static mp_vfs_mount_t *lookup_path(mp_obj_t path_in, mp_obj_t *path_out) {
     const char *path = mp_obj_str_get_str(path_in);
     const char *p_out;
diff --git a/ports/esp32/machine_hw_spi.c b/ports/esp32/machine_hw_spi.c
index 6eb83fc09c..dcf8b3942a 100644
--- a/ports/esp32/machine_hw_spi.c
+++ b/ports/esp32/machine_hw_spi.c
@@ -38,10 +38,10 @@
 #include "soc/spi_pins.h"
 
 // SPI mappings by device, naming used by IDF old/new
-// upython   | ESP32     | ESP32S2   | ESP32S3 | ESP32C3 | ESP32C6
-// ----------+-----------+-----------+---------+---------+---------
-// SPI(id=1) | HSPI/SPI2 | FSPI/SPI2 | SPI2    | SPI2    | SPI2
-// SPI(id=2) | VSPI/SPI3 | HSPI/SPI3 | SPI3    | err     | err
+// MicroPython | ESP32     | ESP32S2   | ESP32S3 | ESP32C3 | ESP32C6
+// ------------+-----------+-----------+---------+---------+---------
+// SPI(id=1)   | HSPI/SPI2 | FSPI/SPI2 | SPI2    | SPI2    | SPI2
+// SPI(id=2)   | VSPI/SPI3 | HSPI/SPI3 | SPI3    | err     | err
 
 // Number of available hardware SPI peripherals.
 #if SOC_SPI_PERIPH_NUM > 2
diff --git a/ports/webassembly/asyncio/core.py b/ports/webassembly/asyncio/core.py
index 9d07bd7b85..eeffa253bc 100644
--- a/ports/webassembly/asyncio/core.py
+++ b/ports/webassembly/asyncio/core.py
@@ -47,7 +47,7 @@ class SingletonGenerator:
             raise self.exc
 
 
-# Pause task execution for the given time (integer in milliseconds, uPy extension)
+# Pause task execution for the given time (integer in milliseconds, MicroPython extension)
 # Use a SingletonGenerator to do it without allocating on the heap
 def sleep_ms(t, sgen=SingletonGenerator()):
     assert sgen.state is None
diff --git a/ports/windows/msvc/paths.props b/ports/windows/msvc/paths.props
index 767772a1aa..a88182f4c9 100644
--- a/ports/windows/msvc/paths.props
+++ b/ports/windows/msvc/paths.props
@@ -31,7 +31,7 @@
     <PyVariantDir Condition="'$(PyVariantDir)' == ''">$(PyWinDir)variants\$(PyVariant)\</PyVariantDir>
     <PyTargetDir Condition="'$(PyTargetDir)' == ''">$(PyBuildDir)</PyTargetDir>
 
-    <!-- All include directories needed for uPy -->
+    <!-- All include directories needed for MicroPython -->
     <PyIncDirs>$(PyIncDirs);$(PyBaseDir);$(PyWinDir);$(PyBuildDir);$(PyWinDir)msvc;$(PyVariantDir)</PyIncDirs>
 
     <!-- Within PyBuildDir different subdirectories are used based on configuration and platform.
diff --git a/py/gc.c b/py/gc.c
index de66137f58..aa9f1e38b8 100644
--- a/py/gc.c
+++ b/py/gc.c
@@ -1245,7 +1245,7 @@ void gc_dump_alloc_table(const mp_print_t *print) {
                     break;
                 }
                 */
-                /* this prints the uPy object type of the head block */
+                /* this prints the MicroPython object type of the head block */
                 case AT_HEAD: {
                     void **ptr = (void **)(area->gc_pool_start + bl * BYTES_PER_BLOCK);
                     if (*ptr == &mp_type_tuple) {
diff --git a/py/mpconfig.h b/py/mpconfig.h
index c25401b8ca..6da872c56c 100644
--- a/py/mpconfig.h
+++ b/py/mpconfig.h
@@ -2099,7 +2099,7 @@ typedef time_t mp_timestamp_t;
 /*****************************************************************************/
 /* Miscellaneous settings                                                    */
 
-// All uPy objects in ROM must be aligned on at least a 4 byte boundary
+// All MicroPython objects in ROM must be aligned on at least a 4 byte boundary
 // so that the small-int/qstr/pointer distinction can be made.  For machines
 // that don't do this (eg 16-bit CPU), define the following macro to something
 // like __attribute__((aligned(4))).
diff --git a/py/objexcept.c b/py/objexcept.c
index 5bf4e672ba..df91c32b1c 100644
--- a/py/objexcept.c
+++ b/py/objexcept.c
@@ -272,7 +272,7 @@ void mp_obj_exception_attr(mp_obj_t self_in, qstr attr, mp_obj_t *dest) {
             // We allow 'exc.__traceback__ = None' assignment as low-level
             // optimization of pre-allocating exception instance and raising
             // it repeatedly - this avoids memory allocation during raise.
-            // However, uPy will keep adding traceback entries to such
+            // However, MicroPython will keep adding traceback entries to such
             // exception instance, so before throwing it, traceback should
             // be cleared like above.
             self->traceback_len = 0;
diff --git a/py/objstr.c b/py/objstr.c
index c81fc682fd..df543041a8 100644
--- a/py/objstr.c
+++ b/py/objstr.c
@@ -1304,7 +1304,7 @@ static vstr_t mp_obj_str_format_helper(const char *str, const char *top, int *ar
                 }
 
                 case '\0':  // No explicit format type implies 'd'
-                case 'n':   // I don't think we support locales in uPy so use 'd'
+                case 'n':   // I don't think we support locales in MicroPython so use 'd'
                 case 'd':
                     mp_print_mp_int(&print, arg, 10, 'a', flags, fill, width, 0);
                     continue;
diff --git a/tests/basics/async_await2.py b/tests/basics/async_await2.py
index 1e3164df93..7c1c85bfa5 100644
--- a/tests/basics/async_await2.py
+++ b/tests/basics/async_await2.py
@@ -2,7 +2,7 @@
 
 import sys
 if sys.implementation.name == 'micropython':
-    # uPy allows normal generators to be awaitables
+    # MicroPython allows normal generators to be awaitables
     coroutine = lambda f: f
 else:
     import types
diff --git a/tests/basics/async_for2.py b/tests/basics/async_for2.py
index aad23a3e5a..530ff390cc 100644
--- a/tests/basics/async_for2.py
+++ b/tests/basics/async_for2.py
@@ -2,7 +2,7 @@
 
 import sys
 if sys.implementation.name == 'micropython':
-    # uPy allows normal generators to be awaitables
+    # MicroPython allows normal generators to be awaitables
     coroutine = lambda f: f
 else:
     import types
diff --git a/tests/basics/async_with2.py b/tests/basics/async_with2.py
index 44421ae917..bcdbfa906a 100644
--- a/tests/basics/async_with2.py
+++ b/tests/basics/async_with2.py
@@ -2,7 +2,7 @@
 
 import sys
 if sys.implementation.name == 'micropython':
-    # uPy allows normal generators to be awaitables
+    # MicroPython allows normal generators to be awaitables
     coroutine = lambda f: f
 else:
     import types
diff --git a/tests/basics/boundmeth1.py b/tests/basics/boundmeth1.py
index fe1b454688..9f08d9bbb2 100644
--- a/tests/basics/boundmeth1.py
+++ b/tests/basics/boundmeth1.py
@@ -1,6 +1,6 @@
 # tests basics of bound methods
 
-# uPy and CPython differ when printing a bound method, so just print the type
+# MicroPython and CPython differ when printing a bound method, so just print the type
 print(type(repr([].append)))
 
 
diff --git a/tests/basics/builtin_range.py b/tests/basics/builtin_range.py
index 728679bc9a..9608a81631 100644
--- a/tests/basics/builtin_range.py
+++ b/tests/basics/builtin_range.py
@@ -54,7 +54,7 @@ print(range(1, 100, 5)[15:5:3])
 print(range(1, 100, -5)[5:15:-3])
 print(range(1, 100, -5)[15:5:3])
 
-# for this case uPy gives a different stop value but the listed elements are still correct
+# for this case MicroPython gives a different stop value but the listed elements are still correct
 print(list(range(7, -2, -4)[2:-2:]))
 
 # zero step
diff --git a/tests/basics/builtin_setattr.py b/tests/basics/builtin_setattr.py
index e4acb14cac..2c9a452c32 100644
--- a/tests/basics/builtin_setattr.py
+++ b/tests/basics/builtin_setattr.py
@@ -21,5 +21,5 @@ except TypeError:
 try:
     setattr(int, 'to_bytes', 1)
 except (AttributeError, TypeError):
-    # uPy raises AttributeError, CPython raises TypeError
+    # MicroPython raises AttributeError, CPython raises TypeError
     print('AttributeError/TypeError')
diff --git a/tests/basics/class_bind_self.py b/tests/basics/class_bind_self.py
index 813f876446..8bece902ca 100644
--- a/tests/basics/class_bind_self.py
+++ b/tests/basics/class_bind_self.py
@@ -52,7 +52,7 @@ print(C.f7(12))
 print(C.f8(13))
 print(C.f9(14))
 
-# not working in uPy
+# not working in MicroPython
 #class C(list):
 #    # this acts like a method and binds self
 #    f1 = list.extend
diff --git a/tests/basics/del_attr.py b/tests/basics/del_attr.py
index 8487b97e31..90a8a5a6f8 100644
--- a/tests/basics/del_attr.py
+++ b/tests/basics/del_attr.py
@@ -35,5 +35,5 @@ except AttributeError:
 try:
     del int.to_bytes
 except (AttributeError, TypeError):
-    # uPy raises AttributeError, CPython raises TypeError
+    # MicroPython raises AttributeError, CPython raises TypeError
     print('AttributeError/TypeError')
diff --git a/tests/basics/del_global.py b/tests/basics/del_global.py
index d740357b03..e1aa074b97 100644
--- a/tests/basics/del_global.py
+++ b/tests/basics/del_global.py
@@ -14,7 +14,7 @@ except NameError:
 try:
     do_del()
 except: # NameError:
-    # FIXME uPy returns KeyError for this
+    # FIXME MicroPython returns KeyError for this
     print("NameError")
 
 # delete globals using a list
diff --git a/tests/basics/del_name.py b/tests/basics/del_name.py
index c92be54d3b..8393b2df92 100644
--- a/tests/basics/del_name.py
+++ b/tests/basics/del_name.py
@@ -10,7 +10,7 @@ except NameError:
 try:
     del x
 except: # NameError:
-    # FIXME uPy returns KeyError for this
+    # FIXME MicroPython returns KeyError for this
     print("NameError")
 
 class C:
diff --git a/tests/basics/frozenset_set.py b/tests/basics/frozenset_set.py
index 3bf456acfd..2b3c683260 100644
--- a/tests/basics/frozenset_set.py
+++ b/tests/basics/frozenset_set.py
@@ -8,5 +8,5 @@ except NameError:
 # "Instances of set are compared to instances of frozenset based on their
 # members. For example:"
 print(set('abc') == frozenset('abc'))
-# This doesn't work in uPy
+# This doesn't work in MicroPython
 #print(set('abc') in set([frozenset('abc')]))
diff --git a/tests/basics/fun_name.py b/tests/basics/fun_name.py
index b2642280a2..8aac35eeaf 100644
--- a/tests/basics/fun_name.py
+++ b/tests/basics/fun_name.py
@@ -16,7 +16,7 @@ except AttributeError:
     print('SKIP')
     raise SystemExit
 
-# __name__ of a bound native method is not implemented in uPy
+# __name__ of a bound native method is not implemented in MicroPython
 # the test here is to make sure it doesn't crash
 try:
     str((1).to_bytes.__name__)
diff --git a/tests/basics/gc1.py b/tests/basics/gc1.py
index 332bf9744c..dff9538b14 100644
--- a/tests/basics/gc1.py
+++ b/tests/basics/gc1.py
@@ -15,13 +15,13 @@ print(gc.isenabled())
 gc.collect()
 
 if hasattr(gc, 'mem_free'):
-    # uPy has these extra functions
+    # MicroPython has these extra functions
     # just test they execute and return an int
     assert type(gc.mem_free()) is int
     assert type(gc.mem_alloc()) is int
 
 if hasattr(gc, 'threshold'):
-    # uPy has this extra function
+    # MicroPython has this extra function
     # check execution and returns
     assert(gc.threshold(1) is None)
     assert(gc.threshold() == 0)
diff --git a/tests/basics/io_iobase.py b/tests/basics/io_iobase.py
index c01ca6a507..de7e4a0b06 100644
--- a/tests/basics/io_iobase.py
+++ b/tests/basics/io_iobase.py
@@ -9,7 +9,7 @@ except (AttributeError, ImportError):
 
 class MyIO(io.IOBase):
     def write(self, buf):
-        # CPython and uPy pass in different types for buf (str vs bytearray)
+        # CPython and MicroPython pass in different types for buf (str vs bytearray)
         print('write', len(buf))
         return len(buf)
 
diff --git a/tests/basics/list_pop.py b/tests/basics/list_pop.py
index 87ed456f85..58bcdd91e4 100644
--- a/tests/basics/list_pop.py
+++ b/tests/basics/list_pop.py
@@ -10,7 +10,7 @@ except IndexError:
 else:
     raise AssertionError("No IndexError raised")
 
-# popping such that list storage shrinks (tests implementation detail of uPy)
+# popping such that list storage shrinks (tests implementation detail of MicroPython)
 l = list(range(20))
 for i in range(len(l)):
     l.pop()
diff --git a/tests/basics/module2.py b/tests/basics/module2.py
index a135601579..d1dc18930f 100644
--- a/tests/basics/module2.py
+++ b/tests/basics/module2.py
@@ -1,4 +1,4 @@
-# uPy behaviour only: builtin modules are read-only
+# MicroPython behaviour only: builtin modules are read-only
 import sys
 try:
     sys.x = 1
diff --git a/tests/basics/parser.py b/tests/basics/parser.py
index 626b67ad7a..6ae5f05ba4 100644
--- a/tests/basics/parser.py
+++ b/tests/basics/parser.py
@@ -7,7 +7,7 @@ except NameError:
     raise SystemExit
 
 # completely empty string
-# uPy and CPy differ for this case
+# MPy and CPy differ for this case
 #try:
 #    compile("", "stdin", "single")
 #except SyntaxError:
diff --git a/tests/basics/python34.py b/tests/basics/python34.py
index 922234d22d..3071b55eff 100644
--- a/tests/basics/python34.py
+++ b/tests/basics/python34.py
@@ -28,7 +28,7 @@ test_syntax("() = []") # can't assign to empty tuple (in 3.6 we can)
 test_syntax("del ()") # can't delete empty tuple (in 3.6 we can)
 
 # from basics/sys1.py
-# uPy prints version 3.4
+# MicroPython prints version 3.4
 import sys
 print(sys.version[:3])
 print(sys.version_info[0], sys.version_info[1])
diff --git a/tests/basics/syntaxerror.py b/tests/basics/syntaxerror.py
index c0702cb245..7b6ef9b755 100644
--- a/tests/basics/syntaxerror.py
+++ b/tests/basics/syntaxerror.py
@@ -86,7 +86,7 @@ test_syntax("yield")
 test_syntax("nonlocal a")
 test_syntax("await 1")
 
-# error on uPy, warning on CPy
+# error on MPy, warning on CPy
 #test_syntax("def f():\n a = 1\n global a")
 
 # default except must be last
@@ -98,7 +98,7 @@ test_syntax("f(1=2)")
 # non-keyword after keyword
 test_syntax("f(a=1, 2)")
 
-# doesn't error on uPy but should
+# doesn't error on MPy but should
 #test_syntax("f(1, i for i in i)")
 
 # all elements of dict/set must be pairs or singles
diff --git a/tests/basics/sys_tracebacklimit.py b/tests/basics/sys_tracebacklimit.py
index 3ae372b8d5..6f575fde65 100644
--- a/tests/basics/sys_tracebacklimit.py
+++ b/tests/basics/sys_tracebacklimit.py
@@ -30,7 +30,7 @@ def print_exc(e):
         if l.startswith("  File "):
             l = l.split('"')
             print(l[0], l[2])
-        # uPy and CPy tracebacks differ in that CPy prints a source line for
+        # MPy and CPy tracebacks differ in that CPy prints a source line for
         # each traceback entry.  In this case, we know that offending line
         # has 4-space indent, so filter it out.
         elif not l.startswith("    "):
diff --git a/tests/basics/tuple1.py b/tests/basics/tuple1.py
index 72bb3f01bf..70ae071898 100644
--- a/tests/basics/tuple1.py
+++ b/tests/basics/tuple1.py
@@ -17,7 +17,7 @@ print(x + (10, 100, 10000))
 x += (10, 11, 12)
 print(x)
 
-# construction of tuple from large iterator (tests implementation detail of uPy)
+# construction of tuple from large iterator (tests implementation detail of MicroPython)
 print(tuple(range(20)))
 
 # unsupported unary operation
diff --git a/tests/cpydiff/modules_struct_fewargs.py b/tests/cpydiff/modules_struct_fewargs.py
index 49b2a3213c..f6346a6793 100644
--- a/tests/cpydiff/modules_struct_fewargs.py
+++ b/tests/cpydiff/modules_struct_fewargs.py
@@ -1,6 +1,6 @@
 """
 categories: Modules,struct
-description: Struct pack with too few args, not checked by uPy
+description: Struct pack with too few args, not checked by MicroPython
 cause: Unknown
 workaround: Unknown
 """
diff --git a/tests/cpydiff/modules_struct_manyargs.py b/tests/cpydiff/modules_struct_manyargs.py
index e3b78930f2..b2ea93b6c9 100644
--- a/tests/cpydiff/modules_struct_manyargs.py
+++ b/tests/cpydiff/modules_struct_manyargs.py
@@ -1,6 +1,6 @@
 """
 categories: Modules,struct
-description: Struct pack with too many args, not checked by uPy
+description: Struct pack with too many args, not checked by MicroPython
 cause: Unknown
 workaround: Unknown
 """
diff --git a/tests/cpydiff/modules_struct_whitespace_in_format.py b/tests/cpydiff/modules_struct_whitespace_in_format.py
index a7a1d2facd..8b609425eb 100644
--- a/tests/cpydiff/modules_struct_whitespace_in_format.py
+++ b/tests/cpydiff/modules_struct_whitespace_in_format.py
@@ -1,6 +1,6 @@
 """
 categories: Modules,struct
-description: Struct pack with whitespace in format, whitespace ignored by CPython, error on uPy
+description: Struct pack with whitespace in format, whitespace ignored by CPython, error on MicroPython
 cause: MicroPython is optimised for code size.
 workaround: Don't use spaces in format strings.
 """
diff --git a/tests/cpydiff/types_float_implicit_conversion.py b/tests/cpydiff/types_float_implicit_conversion.py
index 3726839fac..764c9e4e6e 100644
--- a/tests/cpydiff/types_float_implicit_conversion.py
+++ b/tests/cpydiff/types_float_implicit_conversion.py
@@ -1,6 +1,6 @@
 """
 categories: Types,float
-description: uPy allows implicit conversion of objects in maths operations while CPython does not.
+description: MicroPython allows implicit conversion of objects in maths operations while CPython does not.
 cause: Unknown
 workaround: Objects should be wrapped in ``float(obj)`` for compatibility with CPython.
 """
diff --git a/tests/extmod/asyncio_set_exception_handler.py b/tests/extmod/asyncio_set_exception_handler.py
index 5935f0f4eb..0ac4a62422 100644
--- a/tests/extmod/asyncio_set_exception_handler.py
+++ b/tests/extmod/asyncio_set_exception_handler.py
@@ -12,7 +12,7 @@ def custom_handler(loop, context):
 
 
 async def task(i):
-    # Raise with 2 args so exception prints the same in uPy and CPython
+    # Raise with 2 args so exception prints the same in MicroPython and CPython
     raise ValueError(i, i + 1)
 
 
diff --git a/tests/extmod/hashlib_md5.py b/tests/extmod/hashlib_md5.py
index 5f925fc97d..ebbe9155e0 100644
--- a/tests/extmod/hashlib_md5.py
+++ b/tests/extmod/hashlib_md5.py
@@ -1,8 +1,7 @@
 try:
     import hashlib
 except ImportError:
-    # This is neither uPy, nor cPy, so must be uPy with
-    # hashlib module disabled.
+    # MicroPython with hashlib module disabled.
     print("SKIP")
     raise SystemExit
 
diff --git a/tests/extmod/hashlib_sha1.py b/tests/extmod/hashlib_sha1.py
index af23033a59..46ffb73fcb 100644
--- a/tests/extmod/hashlib_sha1.py
+++ b/tests/extmod/hashlib_sha1.py
@@ -1,8 +1,7 @@
 try:
     import hashlib
 except ImportError:
-    # This is neither uPy, nor cPy, so must be uPy with
-    # hashlib module disabled.
+    # MicroPython with hashlib module disabled.
     print("SKIP")
     raise SystemExit
 
diff --git a/tests/extmod/hashlib_sha256.py b/tests/extmod/hashlib_sha256.py
index f0d07e1482..ffa0922a1c 100644
--- a/tests/extmod/hashlib_sha256.py
+++ b/tests/extmod/hashlib_sha256.py
@@ -1,8 +1,7 @@
 try:
     import hashlib
 except ImportError:
-    # This is neither uPy, nor cPy, so must be uPy with
-    # hashlib module disabled.
+    # MicroPython with hashlib module disabled.
     print("SKIP")
     raise SystemExit
 
diff --git a/tests/extmod/json_dump.py b/tests/extmod/json_dump.py
index 897d33cc81..0beb4f5f85 100644
--- a/tests/extmod/json_dump.py
+++ b/tests/extmod/json_dump.py
@@ -16,11 +16,11 @@ print(s.getvalue())
 # dump to a small-int not allowed
 try:
     json.dump(123, 1)
-except (AttributeError, OSError):  # CPython and uPy have different errors
+except (AttributeError, OSError):  # CPython and MicroPython have different errors
     print("Exception")
 
 # dump to an object not allowed
 try:
     json.dump(123, {})
-except (AttributeError, OSError):  # CPython and uPy have different errors
+except (AttributeError, OSError):  # CPython and MicroPython have different errors
     print("Exception")
diff --git a/tests/extmod/json_dump_iobase.py b/tests/extmod/json_dump_iobase.py
index 94d317b879..81105e36dc 100644
--- a/tests/extmod/json_dump_iobase.py
+++ b/tests/extmod/json_dump_iobase.py
@@ -18,7 +18,7 @@ class S(io.IOBase):
 
     def write(self, buf):
         if type(buf) == bytearray:
-            # uPy passes a bytearray, CPython passes a str
+            # MicroPython passes a bytearray, CPython passes a str
             buf = str(buf, "ascii")
         self.buf += buf
         return len(buf)
diff --git a/tests/extmod/json_dump_separators.py b/tests/extmod/json_dump_separators.py
index 4f8e56dceb..ce39294820 100644
--- a/tests/extmod/json_dump_separators.py
+++ b/tests/extmod/json_dump_separators.py
@@ -25,20 +25,20 @@ for sep in [
     # dump to a small-int not allowed
     try:
         json.dump(123, 1, separators=sep)
-    except (AttributeError, OSError):  # CPython and uPy have different errors
+    except (AttributeError, OSError):  # CPython and MicroPython have different errors
         print("Exception")
 
     # dump to an object not allowed
     try:
         json.dump(123, {}, separators=sep)
-    except (AttributeError, OSError):  # CPython and uPy have different errors
+    except (AttributeError, OSError):  # CPython and MicroPython have different errors
         print("Exception")
 
 
 try:
     s = StringIO()
     json.dump(False, s, separators={"a": 1})
-except (TypeError, ValueError):  # CPython and uPy have different errors
+except (TypeError, ValueError):  # CPython and MicroPython have different errors
     print("Exception")
 
 # invalid separator types
diff --git a/tests/extmod/json_dumps_extra.py b/tests/extmod/json_dumps_extra.py
index 9074416a99..9faf8eefab 100644
--- a/tests/extmod/json_dumps_extra.py
+++ b/tests/extmod/json_dumps_extra.py
@@ -1,4 +1,4 @@
-# test uPy json behaviour that's not valid in CPy
+# test MicroPython json behaviour that's not valid in CPython
 
 try:
     import json
diff --git a/tests/extmod/json_dumps_separators.py b/tests/extmod/json_dumps_separators.py
index a3a9ec308f..0a95f489a0 100644
--- a/tests/extmod/json_dumps_separators.py
+++ b/tests/extmod/json_dumps_separators.py
@@ -39,7 +39,7 @@ for sep in [
 
 try:
     json.dumps(False, separators={"a": 1})
-except (TypeError, ValueError):  # CPython and uPy have different errors
+except (TypeError, ValueError):  # CPython and MicroPython have different errors
     print("Exception")
 
 # invalid separator types
diff --git a/tests/extmod/re_error.py b/tests/extmod/re_error.py
index f61d091328..bd678c9d25 100644
--- a/tests/extmod/re_error.py
+++ b/tests/extmod/re_error.py
@@ -11,7 +11,7 @@ def test_re(r):
     try:
         re.compile(r)
         print("OK")
-    except:  # uPy and CPy use different errors, so just ignore the type
+    except:  # MPy and CPy use different errors, so just ignore the type
         print("Error")
 
 
diff --git a/tests/extmod/re_sub.py b/tests/extmod/re_sub.py
index ecaa66d83d..95ba1d70d6 100644
--- a/tests/extmod/re_sub.py
+++ b/tests/extmod/re_sub.py
@@ -61,7 +61,7 @@ try:
 except:
     print("invalid group")
 
-# invalid group with very large number (to test overflow in uPy)
+# invalid group with very large number (to test overflow in MicroPython)
 try:
     re.sub("(a)", "b\\199999999999999999999999999999999999999", "a")
 except:
diff --git a/tests/float/string_format2.py b/tests/float/string_format2.py
index 7a36f4d2f9..cdea4c1197 100644
--- a/tests/float/string_format2.py
+++ b/tests/float/string_format2.py
@@ -144,7 +144,7 @@ if full_tests:
             for alignment in ("", "<", ">", "=", "^"):
                 for fill in ("", " ", "0", "@"):
                     for sign in ("", "+", "-", " "):
-                        # An empty precision defaults to 6, but when uPy is
+                        # An empty precision defaults to 6, but when MicroPython is
                         # configured to use a float, we can only use a
                         # precision of 6 with numbers less than 10 and still
                         # get results that compare to CPython (which uses
@@ -164,7 +164,7 @@ if full_tests:
         for alignment in ("", "<", ">", "=", "^"):
             for fill in ("", " ", "0", "@"):
                 for sign in ("", "+", "-", " "):
-                    # An empty precision defaults to 6, but when uPy is
+                    # An empty precision defaults to 6, but when MicroPython is
                     # configured to use a float, we can only use a
                     # precision of 6 with numbers less than 10 and still
                     # get results that compare to CPython (which uses
diff --git a/tests/float/string_format_modulo.py b/tests/float/string_format_modulo.py
index 3c206b7393..5531464335 100644
--- a/tests/float/string_format_modulo.py
+++ b/tests/float/string_format_modulo.py
@@ -6,7 +6,7 @@ print("%i" % 1.0)
 print("%u" % 1.0)
 
 # these 3 have different behaviour in Python 3.x versions
-# uPy raises a TypeError, following Python 3.5 (earlier versions don't)
+# MicroPython raises a TypeError, following Python 3.5 (earlier versions don't)
 # print("%x" % 18.0)
 # print("%o" % 18.0)
 # print("%X" % 18.0)
diff --git a/tests/frozen/frozentest.mpy b/tests/frozen/frozentest.mpy
index 99581617ac..ccdf5e1a95 100644
Binary files a/tests/frozen/frozentest.mpy and b/tests/frozen/frozentest.mpy differ
diff --git a/tests/frozen/frozentest.py b/tests/frozen/frozentest.py
index 78cdd60bf0..74bdfb3b26 100644
--- a/tests/frozen/frozentest.py
+++ b/tests/frozen/frozentest.py
@@ -1,4 +1,4 @@
-print("uPy")
+print("interned")
 print("a long string that is not interned")
 print("a string that has unicode αβγ chars")
 print(b"bytes 1234\x01")
diff --git a/tests/io/builtin_print_file.py b/tests/io/builtin_print_file.py
index 822356a6cc..e00f58635a 100644
--- a/tests/io/builtin_print_file.py
+++ b/tests/io/builtin_print_file.py
@@ -13,5 +13,5 @@ print("test", file=sys.stdout)
 
 try:
     print(file=1)
-except (AttributeError, OSError):  # CPython and uPy differ in error message
+except (AttributeError, OSError):  # CPython and MicroPython differ in error message
     print("Error")
diff --git a/tests/io/file_seek.py b/tests/io/file_seek.py
index 3990df8409..b9f9593786 100644
--- a/tests/io/file_seek.py
+++ b/tests/io/file_seek.py
@@ -30,5 +30,5 @@ f.close()
 try:
     f.seek(1)
 except (OSError, ValueError):
-    # CPy raises ValueError, uPy raises OSError
+    # CPy raises ValueError, MPy raises OSError
     print("OSError or ValueError")
diff --git a/tests/micropython/decorator_error.py b/tests/micropython/decorator_error.py
index 94772ac1e5..b5eae65b29 100644
--- a/tests/micropython/decorator_error.py
+++ b/tests/micropython/decorator_error.py
@@ -1,4 +1,4 @@
-# test syntax errors for uPy-specific decorators
+# test syntax errors for MicroPython-specific decorators
 
 
 def test_syntax(code):
diff --git a/tests/micropython/heapalloc_traceback.py b/tests/micropython/heapalloc_traceback.py
index 5ded8c5f0c..1743d4956d 100644
--- a/tests/micropython/heapalloc_traceback.py
+++ b/tests/micropython/heapalloc_traceback.py
@@ -34,7 +34,7 @@ test()
 buf = io.StringIO()
 sys.print_exception(global_exc, buf)
 for l in buf.getvalue().split("\n"):
-    # uPy on pyboard prints <stdin> as file, so remove filename.
+    # MicroPython on pyboard prints <stdin> as file, so remove filename.
     if l.startswith("  File "):
         l = l.split('"')
         print(l[0], l[2])
diff --git a/tests/misc/non_compliant.py b/tests/misc/non_compliant.py
index dd62f63255..54ad2960e4 100644
--- a/tests/misc/non_compliant.py
+++ b/tests/misc/non_compliant.py
@@ -39,7 +39,7 @@ try:
 except NotImplementedError:
     print("NotImplementedError")
 
-# uPy raises TypeError, should be ValueError
+# MicroPython raises TypeError, should be ValueError
 try:
     "%c" % b"\x01\x02"
 except (TypeError, ValueError):
@@ -99,10 +99,10 @@ try:
 except NotImplementedError:
     print("NotImplementedError")
 
-# struct pack with too many args, not checked by uPy
+# struct pack with too many args, not checked by MicroPython
 print(struct.pack("bb", 1, 2, 3))
 
-# struct pack with too few args, not checked by uPy
+# struct pack with too few args, not checked by MicroPython
 print(struct.pack("bb", 1))
 
 # array slice assignment with unsupported RHS
diff --git a/tests/misc/non_compliant_lexer.py b/tests/misc/non_compliant_lexer.py
index e1c21f3d71..04c605953e 100644
--- a/tests/misc/non_compliant_lexer.py
+++ b/tests/misc/non_compliant_lexer.py
@@ -11,7 +11,7 @@ def test(code):
         print("NotImplementedError")
 
 
-# uPy requires spaces between literal numbers and keywords, CPy doesn't
+# MPy requires spaces between literal numbers and keywords, CPy doesn't
 try:
     eval("1and 0")
 except SyntaxError:
diff --git a/tests/misc/print_exception.py b/tests/misc/print_exception.py
index d41478360f..fdf5711c57 100644
--- a/tests/misc/print_exception.py
+++ b/tests/misc/print_exception.py
@@ -20,11 +20,11 @@ def print_exc(e):
     print_exception(e, buf)
     s = buf.getvalue()
     for l in s.split("\n"):
-        # uPy on pyboard prints <stdin> as file, so remove filename.
+        # MPy on pyboard prints <stdin> as file, so remove filename.
         if l.startswith("  File "):
             l = l.split('"')
             print(l[0], l[2])
-        # uPy and CPy tracebacks differ in that CPy prints a source line for
+        # MPy and CPy tracebacks differ in that CPy prints a source line for
         # each traceback entry. In this case, we know that offending line
         # has 4-space indent, so filter it out.
         elif not l.startswith("    "):
@@ -89,7 +89,7 @@ try:
 except Exception as e:
     print_exc(e)
 
-# Test non-stream object passed as output object, only valid for uPy
+# Test non-stream object passed as output object, only valid for MicroPython
 if hasattr(sys, "print_exception"):
     try:
         sys.print_exception(Exception, 1)
diff --git a/tests/ports/unix/extra_coverage.py b/tests/ports/unix/extra_coverage.py
index 493d02cde9..2087e7ea2a 100644
--- a/tests/ports/unix/extra_coverage.py
+++ b/tests/ports/unix/extra_coverage.py
@@ -128,7 +128,7 @@ from frzqstr import returns_NULL
 
 print(returns_NULL())
 
-# test for freeze_mpy
+# test for freeze_mpy (importing prints several lines)
 import frozentest
 
 print(frozentest.__file__)
diff --git a/tests/ports/unix/extra_coverage.py.exp b/tests/ports/unix/extra_coverage.py.exp
index 5b6e1f3f0f..d11e5ee6f4 100644
--- a/tests/ports/unix/extra_coverage.py.exp
+++ b/tests/ports/unix/extra_coverage.py.exp
@@ -250,7 +250,7 @@ b'\x00\xff'
 frzmpy4 1
 frzmpy4 2
 NULL
-uPy
+interned
 a long string that is not interned
 a string that has unicode αβγ chars
 b'bytes 1234\x01'