diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 0d9bcc4..1aeddbc 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -18,11 +18,18 @@ jobs:
           - "3.12"
           - "3.13"
           - "3.14"
+          - "3.15-dev"
         extras:
-          - "[test,docs,zodb]"
-        # include:
-        #   - python-version: "3.13"
-        #     extras: "[test,docs,gevent,pyramid]"
+          - "[test,docs,zodb,orjson]"
+        include:
+          # orjson 3.11.9 doesn't currently support
+          # being built for free-threaded python, so if we wanted
+          # to test there, we'd need to substitute it, most likely by
+          # moving it to an extra.
+          - python-version: "3.14t"
+            extras: "[test,docs,zodb]"
+          - python-version: "3.15t-dev"
+            extras: "[test,docs,zodb]"
 
     runs-on: ubuntu-latest
     steps:
@@ -38,13 +45,20 @@ jobs:
         python -m pip install -U pip setuptools wheel
         python -m pip install -U coverage
         python -m pip install -v -U -e ".${{ matrix.extras }}"
+    - name: Disable GIL
+      if: ${{endsWith(matrix.python-version, 't') || endsWith(matrix.python-version, 't-dev')}}
+      # zope.hookable 8.2/zope.proxy 7.2 currently enables the gil
+      run: |
+        echo PYTHON_GIL=0 >> $GITHUB_ENV
     - name: Test
       run: |
         python -m coverage run -m zope.testrunner --test-path=src  --auto-color --auto-progress
         PURE_PYTHON=1 coverage run -a -m zope.testrunner --test-path=src  --auto-color --auto-progress
+    - name: Docs
+      if: matrix.python-version == '3.14'
+      # Requires orjson
+      run: |
         coverage run -a -m sphinx -b doctest -d docs/_build/doctrees docs docs/_build/doctests
-        coverage combine || true
-        coverage report -i || true
     - name: Lint
       if: matrix.python-version == '3.14'
       run: |
@@ -54,6 +68,10 @@ jobs:
       run: |
         python -m pip uninstall -y ZODB zope.dublincore  persistent zope.container BTrees
         PURE_PYTHON=1 coverage run -a -m zope.testrunner --test-path=src  --auto-color --auto-progress
+    - name: Combine Coverage
+      run: |
+        coverage combine || true
+        coverage report -i || true
     - name: Submit to Coveralls
       uses: coverallsapp/github-action@v2
       with:
@@ -75,7 +93,7 @@ jobs:
     # We use a regular Python matrix entry to share as much code as possible.
     strategy:
       matrix:
-        python-version: [3.12]
+        python-version: [3.14]
         image:
           - manylinux_2_28_x86_64
           - manylinux_2_28_aarch64
diff --git a/.readthedocs.yml b/.readthedocs.yml
index 11bc75d..c4396a1 100644
--- a/.readthedocs.yml
+++ b/.readthedocs.yml
@@ -24,7 +24,7 @@ build:
   # os is required for some reason
   os: ubuntu-22.04
   tools:
-    python: "3.11"
+    python: "3.14"
 
 python:
   install:
@@ -32,3 +32,4 @@ python:
       path: .
       extra_requirements:
         - docs
+        - orjson
diff --git a/CHANGES.rst b/CHANGES.rst
index 53b5729..361d6ea 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -3,10 +3,18 @@
 =========
 
 
-3.1.1 (unreleased)
+3.2.0 (unreleased)
 ==================
 
-- Nothing changed yet.
+- Drop support for Python 3.10.
+- Add support for Python 3.15.
+- Move the ``orjson`` dependency to the ``orjson`` extra
+  for compatibility with free-threaded Python. If you're using regular
+  Python, it is highly recommended to install this extra.
+- Add support for free-threaded CPython. However, note that some
+  dependencies, most notably orjson, cannot
+  currently be installed on free-threaded CPython, and other
+  dependencies may currently require enabling the GIL.
 
 
 3.1.0 (2026-05-08)
diff --git a/docs/basics.rst b/docs/basics.rst
index f3f1e7d..ff9510e 100644
--- a/docs/basics.rst
+++ b/docs/basics.rst
@@ -60,6 +60,23 @@ concerns should be kept as separated as possible from our model
 objects. Ideally, we should be able to use third-party objects that we
 have no control over seamlessly in external and internal data.
 
+Installation
+============
+
+This package is installed from PyPI::
+
+  pip install nti.externalization[orjson,zodb]
+
+It has some extras:
+
+orjson
+   Highly recommended for a faster dumping and loading experience. As
+   of at least orjson 3.11.9, however, this is incompatible with
+   free-threaded Python.
+zodb
+   Optional; provides support for BTrees, persistent objects, intids, and
+   container proxies.
+
 Getting Started
 ===============
 
@@ -248,7 +265,7 @@ others:
 
   >>> internal.creator = u'sjohnson'
   >>> internal.createdTime = 123456
-  >>> pprint(to_external_object(internal))
+  >>> pprint(to_external_object(internal), compact=True, indent=1)
   {'Class': 'ExternalObject',
    'CreatedTime': 123456,
    'Creator': 'sjohnson',
@@ -337,7 +354,7 @@ Now we can register and use it as before:
    ...    postal_code=u'95014',
    ...    country=u'USA')
    >>> external = to_external_object(address)
-   >>> pprint(external)
+   >>> pprint(external, compact=True, indent=1)
    {'Class': 'Address',
     'city': 'Cupertino',
     'country': 'USA',
@@ -473,7 +490,7 @@ demonstrating that nested schemas and objects are possible.
    ...     realname=u'Steve Jobs',
    ... )
    >>> external = to_external_object(user_profile)
-   >>> pprint(external)
+   >>> pprint(external, compact=True, indent=1)
    {'Class': 'UserProfile',
     'MimeType': 'application/vnd.nextthought.benchmarks.userprofile',
     'addresses': {'home': {'Class': 'Address',
diff --git a/docs/conf.py b/docs/conf.py
index 8d4ed18..b2b3f9b 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -78,7 +78,7 @@
 #
 # This is also used if you do content translation via gettext catalogs.
 # Usually you set "language" from the command line for these cases.
-language = None
+language = 'en'
 
 # List of patterns, relative to source directory, that match files and
 # directories to ignore when looking for source files.
diff --git a/docs/externalization.rst b/docs/externalization.rst
index adef431..bd4728f 100644
--- a/docs/externalization.rst
+++ b/docs/externalization.rst
@@ -85,7 +85,7 @@ We'll register our adapter and externalize:
    >>> from zope import component
    >>> component.provideSubscriptionAdapter(PrivateAddressDecorator)
    >>> from pprint import pprint
-   >>> pprint(to_external_object(home_address))
+   >>> pprint(to_external_object(home_address), compact=True, indent=1)
    {'Class': 'Address',
     'MimeType': 'application/vnd.nextthought.benchmarks.address',
     'country': 'USA',
@@ -118,7 +118,7 @@ look for a request):
    :pyversion: > 3.3
 
    >>> component.provideSubscriptionAdapter(LinkAddressDecorator)
-   >>> pprint(to_external_object(home_address, request=Request()))
+   >>> pprint(to_external_object(home_address, request=Request()), compact=True, indent=1)
    {'Class': 'Address',
     'MimeType': 'application/vnd.nextthought.benchmarks.address',
     'country': 'USA',
diff --git a/make-manylinux b/make-manylinux
index 4837235..163b1f2 100755
--- a/make-manylinux
+++ b/make-manylinux
@@ -13,7 +13,7 @@ export TRAVIS=true
 # know. The env var works for pip 20.
 export PIP_NO_PYTHON_VERSION_WARNING=1
 export PIP_NO_WARN_SCRIPT_LOCATION=1
-
+export PIP_ROOT_USER_ACTION=ignore
 
 if [ -d /project ] && [ -d /opt/python ]; then
     # Running inside docker
@@ -44,9 +44,9 @@ if [ -d /project ] && [ -d /opt/python ]; then
     OPATH="$PATH"
     which auditwheel
     echo @@@@@@@@@@@@@@@@@@@@@@
-    echo Will build /opt/python/cp{310,311,312,313,314}*
+    echo Will build /opt/python/cp{311,312,313,314,315}*
 
-    for variant in `ls -d /opt/python/cp{314,313,310,311,312}*`; do
+    for variant in `ls -d /opt/python/cp{315,314,313,311,312}*`; do
 
         export PATH="$variant/bin:$OPATH"
         echo "Building $variant $(python --version)"
diff --git a/setup.py b/setup.py
index 2e49cee..47c239b 100755
--- a/setup.py
+++ b/setup.py
@@ -133,6 +133,7 @@ def _c(m):
                 'language_level': '3',
                 'always_allow_keywords': False,
                 'nonecheck': False,
+                'freethreading_compatible': True,
             },
         )
     except ValueError:
@@ -147,7 +148,7 @@ def _c(m):
 
 setup(
     name='nti.externalization',
-    version='3.1.1.dev0',
+    version='3.2.0.dev0',
     author='Jason Madden',
     author_email='jason@seecoresoftware.com',
     description="NTI Externalization",
@@ -160,11 +161,11 @@ def _c(m):
         'Operating System :: OS Independent',
         'Programming Language :: Python :: 3',
         'Programming Language :: Python :: 3 :: Only',
-        'Programming Language :: Python :: 3.10',
         'Programming Language :: Python :: 3.11',
         'Programming Language :: Python :: 3.12',
         'Programming Language :: Python :: 3.13',
         'Programming Language :: Python :: 3.14',
+        'Programming Language :: Python :: 3.15',
         'Programming Language :: Python :: Implementation :: CPython',
     ],
     url="https://github.com/OpenNTI/nti.externalization",
@@ -179,7 +180,7 @@ def _c(m):
         'PyYAML >= 5.1',
         'isodate',
         'pytz',
-        'orjson >= 3.11.9',
+
         'transaction',
         'zope.component >= 4.6.1',
         'zope.configuration >= 4.4.0',
@@ -212,7 +213,10 @@ def _c(m):
         'benchmarks': [
             'pyperf',
         ],
+        'orjson': [
+            'orjson >= 3.11.9',
+        ]
     },
     entry_points=entry_points,
-    python_requires=">=3.10",
+    python_requires=">=3.11",
 )
diff --git a/src/nti/externalization/representation.py b/src/nti/externalization/representation.py
index 85b918f..81d994e 100644
--- a/src/nti/externalization/representation.py
+++ b/src/nti/externalization/representation.py
@@ -20,7 +20,13 @@ class POSError(Exception): # type:ignore[no-redef]
         """Mock"""
 else:
     from ZODB.POSException import POSError # type:ignore[no-redef]
-import orjson
+try:
+    import orjson
+    _HAS_ORJSON = True
+except ModuleNotFoundError:
+    import json
+    _HAS_ORJSON = False
+
 import yaml
 from zope import component
 from zope import interface
@@ -39,6 +45,8 @@ class POSError(Exception): # type:ignore[no-redef]
     'to_json_representation_sorted',
     'WithRepr',
     'JsonRepresenter',
+    'OrJsonRepresenter',
+    'StdJsonRepresenter',
     'YamlRepresenter',
 ]
 
@@ -102,7 +110,8 @@ def to_json_representation_fast(obj) -> bytes:
     and additional parameters to optimize for speed.
 
     Note that this bypasses utility lookup and directly
-    uses :class:`JsonRepresenter`
+    uses :class:`JsonRepresenter`. It is also only
+    fastest when using orjson.
 
     .. versionadded:: 3.0.0
     .. versionchanged:: 3.1.0
@@ -148,7 +157,7 @@ def _second_pass_to_external_object(obj):
 
 @interface.named(EXT_REPR_JSON)
 @interface.implementer(IExternalObjectIO)
-class JsonRepresenter(object):
+class OrJsonRepresenter:
     """
     Default IO object using ``orjson`` for JSON input/output.
     """
@@ -169,7 +178,9 @@ def dump(obj, fp=None, sort_keys=False, as_str=True, **_unused) -> str|bytes:
            Added the *sort_keys* parameter, defaulting to false for speed.
            Added the *as_str* parameter, defaulting to true for backwards compatibility.
            If set to false, then a bytes object will be returned (and written to any
-           *fp*). Bytes is orjson's native output format.
+           *fp*). Bytes is orjson's native output format, meaning no encoding/decoding is
+           required when this is false.
+
 
            Other keyword arguments are ignored.
 
@@ -186,6 +197,56 @@ def dump(obj, fp=None, sort_keys=False, as_str=True, **_unused) -> str|bytes:
     def load(self, stream):
         return orjson.loads(stream)
 
+
+@interface.named(EXT_REPR_JSON)
+@interface.implementer(IExternalObjectIO)
+class StdJsonRepresenter:
+    """
+    Default IO object using :mod:`json` for JSON input/output.
+    """
+
+    @staticmethod
+    def dump(obj, fp=None, sort_keys=False, as_str=True, **_unused) -> str|bytes:
+        """
+        dump(obj, fp=None, sort_keys=False, as_str=True) -> str|bytes
+
+        Given an object that is known to already be in an externalized form,
+        convert it to JSON. This can be about 10% faster then requiring a pass
+        across all the sub-objects of the object to check that they are in external
+        form, while still handling a few corner cases with a second-pass conversion.
+        (These things creep in during the object decorator phase and are usually
+        links.)
+
+        .. versionchanged:: 3.0.0
+           Added the *sort_keys* parameter, defaulting to false for speed.
+           Added the *as_str* parameter, defaulting to true for backwards compatibility
+           and speed.
+           If set to false, then a bytes object will be returned (and written to any
+           *fp*). Because str is the standard library's default output format, this
+           requires decoding.
+
+           Other keyword arguments are ignored.
+
+        """
+        result = json.dumps(obj, # pylint: disable=used-before-assignment
+                            sort_keys=sort_keys,
+                            default=_second_pass_to_external_object)
+        if not as_str:
+            result = result.encode('utf-8') # type:ignore[assignment]
+        if fp:
+            return fp.write(result)
+        return result
+
+    def load(self, stream):
+        return json.loads(stream)
+
+
+if _HAS_ORJSON:
+    JsonRepresenter = OrJsonRepresenter
+else:
+    JsonRepresenter = StdJsonRepresenter # type:ignore
+
+
 # This is meant for dumping already externalized objects, but
 # because of the second_pass_to_external_object default,
 # it will actually dump any dumpable object by first externalizing
@@ -255,7 +316,7 @@ def construct_yaml_str(self, node):
 @interface.implementer(IExternalObjectIO)
 class YamlRepresenter(object):
     """
-    Default IO object using ``yaml`` for object input/output.
+    Default IO object using :mod:`yaml` for object input/output.
     """
 
     @staticmethod
diff --git a/src/nti/externalization/tests/test_docs.py b/src/nti/externalization/tests/test_docs.py
index c51edfe..9f87a89 100644
--- a/src/nti/externalization/tests/test_docs.py
+++ b/src/nti/externalization/tests/test_docs.py
@@ -37,6 +37,11 @@
 manuel.codeblock.CODEBLOCK_START = CODEBLOCK_START
 
 def test_suite():
+    try:
+        import orjson
+    except ModuleNotFoundError:
+        orjson = None # type:ignore
+
     here = os.path.dirname(__file__)
     while not os.path.exists(os.path.join(here, 'setup.py')):
         here = os.path.join(here, '..')
@@ -48,7 +53,8 @@ def test_suite():
         'basics.rst',
         'externalization.rst',
         'internalization.rst',
-    )
+    ) if orjson else ()
+
     paths = [os.path.join(docs, f) for f in files_to_test]
     kwargs = {'tearDown': lambda _: cleanup.cleanUp()}
     m = manuel.ignore.Manuel()
diff --git a/src/nti/externalization/tests/test_externalization.py b/src/nti/externalization/tests/test_externalization.py
index d6dad49..d3157f8 100644
--- a/src/nti/externalization/tests/test_externalization.py
+++ b/src/nti/externalization/tests/test_externalization.py
@@ -832,6 +832,10 @@ def toExternalObject(self, **_kwargs):
     def test_recursive_call_on_creator(self):
         # Make sure that we properly handle recursive calls on a
         # field we want to pre-convert to a str, creator.
+        try:
+            __import__('orjson')
+        except ModuleNotFoundError:
+            self.skipTest('Requires orjson')
 
         class O(object):
             def __init__(self):
diff --git a/src/nti/externalization/tests/test_representation.py b/src/nti/externalization/tests/test_representation.py
index 6f56556..2dffaf7 100644
--- a/src/nti/externalization/tests/test_representation.py
+++ b/src/nti/externalization/tests/test_representation.py
@@ -221,6 +221,10 @@ def _expected_nan_str(self, val):
 
     def test_dump_decimal_nan(self):
         import decimal
+        try:
+            __import__('orjson')
+        except ModuleNotFoundError:
+            self.skipTest('Requires orjson') # type:ignore
         rep = self._makeOne()
 
         for f in float('-nan'), float('nan'):
@@ -235,6 +239,11 @@ def _expected_decimal_inf_val(self, val):
 
     def test_dump_decimal_inf(self):
         import decimal
+        try:
+            __import__('orjson')
+        except ModuleNotFoundError:
+            self.skipTest('Requires orjson') # type:ignore
+
         rep = self._makeOne()
 
         for f in float('-inf'), float('inf'):
diff --git a/tox.ini b/tox.ini
index 61ad20f..7d112d0 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,6 +1,6 @@
 [tox]
 envlist =
-   py310,py311,py312,py313,py314,py314-pure,coverage,docs,lint
+   py311,py312,py313,py314,py314-pure,py314t,py315t,coverage,docs,lint
 
 [testenv]
 usedevelop = true
@@ -9,10 +9,12 @@ commands =
 extras =
     test
     zodb
+    orjson
 setenv =
     pure: PURE_PYTHON=1
     ZOPE_INTERFACE_STRICT_IRO=1
 
+
 [testenv:coverage]
 usedevelop = true
 basepython =
@@ -30,12 +32,28 @@ setenv =
 extras =
     test
 
+[testenv:py314t]
+setenv:
+    PYTHON_GIL=0
+extras =
+    test
+    zodb
+
+[testenv:py315t]
+setenv:
+    PYTHON_GIL=0
+extras =
+    test
+    zodb
+
 [testenv:docs]
 commands =
     sphinx-build -b html -d docs/_build/doctrees docs docs/_build/html
     # XXX: Fix doctests
     #python -m sphinx -b doctest -d docs/_build/doctrees docs docs/_build/doctests
-extras = docs
+extras =
+    docs
+    orjson
 setenv =
     PURE_PYTHON = 1