diff --git a/MANIFEST.in b/MANIFEST.in
index c646b6968..26b821f83 100644
--- a/MANIFEST.in
+++ b/MANIFEST.in
@@ -1,8 +1,7 @@
 include src/rez/data/*
-include src/rez/rezconfig
 include src/rez/completion/*
 include src/rez/vendor/distlib/*.exe
 include src/rezgui/rezguiconfig
 include src/rezgui/icons/*
 recursive-include src/rez README*
-recursive-include src/rezplugins *.cmake Doxyfile rezconfig
+recursive-include src/rezplugins *.cmake Doxyfile
diff --git a/setup.py b/setup.py
index 34b9b396d..ad11b1edb 100644
--- a/setup.py
+++ b/setup.py
@@ -76,7 +76,6 @@ def find_files(pattern, path=None, root="rez"):
             find_files('*', 'data') +
             find_files('*.exe', 'vendor/distlib'),
         'rezplugins':
-            find_files('rezconfig', root='rezplugins') +
             find_files('*.cmake', 'build_system', root='rezplugins') +
             find_files('*', 'build_system/template_files', root='rezplugins'),
         'rezgui':
diff --git a/src/build_utils/license/apply_copyright b/src/build_utils/license/apply_copyright
index 880cfa583..daa048eb9 100755
--- a/src/build_utils/license/apply_copyright
+++ b/src/build_utils/license/apply_copyright
@@ -7,7 +7,6 @@ fi
 
 # remove copyright
 find ./src/rez/data -name '*.py' > .lic.tmp
-find ./src/rez/backport -name '*.py' >> .lic.tmp
 cat .lic.tmp | xargs -i ./src/build_utils/license/change_copyright -so {}
 
 # add copyright
diff --git a/src/rezplugins/build_process/rezconfig b/src/rezplugins/build_process/rezconfig
deleted file mode 100644
index e69de29bb..000000000
diff --git a/src/rezplugins/build_process/rezconfig.py b/src/rezplugins/build_process/rezconfig.py
new file mode 100644
index 000000000..ac31011e1
--- /dev/null
+++ b/src/rezplugins/build_process/rezconfig.py
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: Apache-2.0
+# Copyright Contributors to the Rez Project
diff --git a/src/rezplugins/build_system/rezconfig b/src/rezplugins/build_system/rezconfig
deleted file mode 100644
index 18ddea371..000000000
--- a/src/rezplugins/build_system/rezconfig
+++ /dev/null
@@ -1,21 +0,0 @@
-# TODO remove this file in PR for https://github.com/AcademySoftwareFoundation/rez/issues/525,
-# it is unused
-
-cmake:
-    # The name of the CMake build system to use, valid options are
-    # eclipse, make, xcode and codeblocks.
-    build_system: make
-
-    # The name of the CMake build target to use, valid options are Debug,
-    # Release and RelWithDebInfo.
-    build_target: Release
-
-    # A list of default arguments to be passed to the cmake binary.
-    cmake_args:
-    - '-DCMAKE_SKIP_RPATH=1'
-
-    # Optionally specify an explicit cmake executable to use for building.
-    cmake_binary:
-
-    # If True, install pyc files when the 'rez_install_python' macro is used.
-    install_pyc: true
diff --git a/src/rezplugins/package_repository/rezconfig b/src/rezplugins/package_repository/rezconfig.py
similarity index 87%
rename from src/rezplugins/package_repository/rezconfig
rename to src/rezplugins/package_repository/rezconfig.py
index 811b8215d..85eba726c 100644
--- a/src/rezplugins/package_repository/rezconfig
+++ b/src/rezplugins/package_repository/rezconfig.py
@@ -1,15 +1,19 @@
-filesystem:
+# SPDX-License-Identifier: Apache-2.0
+# Copyright Contributors to the Rez Project
+
+
+filesystem = {
     # The mechanism used to create the lockfile. If set to 'default', this will
     # use hardlinks if the 'os.link' method is present, otherwise mkdir is used.
     # It can also be explicitly set to use only 'hardlink', or only 'mkdir'.
     # Valid options are 'default', 'mkdir', or 'hardlink'
-    file_lock_type: default
+    "file_lock_type": "default",
 
     # The timeout to use when creating file locks. This is done when a variant is
     # installed into an existing package, to prevent multiple file writes at
     # once (which could result in a variant install getting lost). The timeout
     # value is in seconds. A value of zero indicates no timeout.
-    file_lock_timeout: 10
+    "file_lock_timeout": 10,
 
     # The relative directory, under the repository location, where file locks
     # are created. You might need to use this option when file permissions are
@@ -21,13 +25,13 @@
     #
     # Note: The directory can have any name, but we suggest '.lock' as the
     # standard convention.
-    file_lock_dir:
+    "file_lock_dir": None,
 
     # If True, verify that a potential package directory contains a package.py /
     # package.yaml file before treating it as a package. There *shouldn't* be
     # non-packages in these directories, and the solver is faster if this value
     # is False, because a lot of file stats are avoided.
-    check_package_definition_files: false
+    "check_package_definition_files": False,
 
     # A list of filenames that are expected to contain Rez definitions.
     # The list will be checked in top to bottom order, and the first filename
@@ -39,5 +43,7 @@
     # released package filename, regardless of the definition filename present
     # in the source.
     #
-    package_filenames:
-    - 'package'
+    "package_filenames": [
+        "package"
+    ]
+}
diff --git a/src/rezplugins/release_hook/rezconfig b/src/rezplugins/release_hook/rezconfig.py
similarity index 69%
rename from src/rezplugins/release_hook/rezconfig
rename to src/rezplugins/release_hook/rezconfig.py
index 1dd9ce24d..acec27c73 100644
--- a/src/rezplugins/release_hook/rezconfig
+++ b/src/rezplugins/release_hook/rezconfig.py
@@ -1,18 +1,25 @@
-emailer:
+# SPDX-License-Identifier: Apache-2.0
+# Copyright Contributors to the Rez Project
+
+
+emailer = {
     # SMTP host.
-    smtp_host: ''
+    "smtp_host": '',
 
     # SMTP port.
-    smtp_port: 25
+    "smtp_port": 25,
 
     # The address that post-release emails appear to come from.
-    sender: '{system.user}@rez-release.com'
+    "sender": '{system.user}@rez-release.com',
 
     # List of recipients of post-release emails; OR, path to recipients config
     # file (see emailer-recipients-example.yaml). If this is a string that
     # contains '@' and doesn't refer to a filepath, then it's treated as an
     # email address.
-    recipients: []
+    "recipients": [],
+
+    # Subject format - supports the same object formatting available in 'body'
+    "subject": '[rez] [release] {system.user} released {package.qualified_name}',
 
     # Message format. Available objects for formatting are:
     # - package: The package that is being released.
@@ -25,43 +32,42 @@
     # - variants: Namespace for info about the variants that were released:
     #   - count: The number of variants that were released;
     #   - paths: Newline-separated paths to the root of each variant.
-    body: |
-        Package '{package.qualified_name}' was released by {system.user}@{system.fqdn}.
-
-        USER: {system.user}
-        PACKAGE: {package.qualified_name}
-        RELEASED TO: {release.path}
-        PREVIOUS VERSION: {release.previous_version}
-        REZ VERSION: {system.rez_version}
+    "body": """
+Package '{package.qualified_name}' was released by {system.user}@{system.fqdn}.
 
-        {variants.count} VARIANTS:
-        {variants.paths}
+USER: {system.user}
+PACKAGE: {package.qualified_name}
+RELEASED TO: {release.path}
+PREVIOUS VERSION: {release.previous_version}
+REZ VERSION: {system.rez_version}
 
-        MESSAGE:
-        {release.message}
+{variants.count} VARIANTS:
+{variants.paths}
 
-        CHANGELOG:
-        {release.changelog}
+MESSAGE:
+{release.message}
 
-    # Subject format - supports the same object formatting available in 'body'
-    subject: '[rez] [release] {system.user} released {package.qualified_name}'
+CHANGELOG:
+{release.changelog}
+""".strip()
+}
 
-command:
+command = {
     # If true, print the commands that are being run
-    print_commands: true
+    "print_commands": True,
 
     # If true, print output of commands.
-    print_output: true
+    "print_output": True,
 
     # If true, print failed commands to stderr
-    print_error: true
+    "print_error": True,
 
     # If true, cancel the package release if a pre-* command fails.
-    cancel_on_error: true
+    "cancel_on_error": True,
 
     # If true, skip all commands after a failed command. This does not cancel
     # the package release.
-    stop_on_error: true
+    "stop_on_error": True,
 
     # List of commands to execute prior to build, in given order.
     # Each item is a dict containing:
@@ -82,8 +88,7 @@
     # - release: Namespace for info about the current release, contains:
     #   - path: Installation path of release.
     #
-    # Also, any environment variables references in command arguments are
-    # expanded also.
+    # Any environment variables references in command arguments are expanded.
     #
     # Example:
     # pre_build_commands
@@ -91,35 +96,37 @@
     #   args: '-a -l'
     #   user: root
     #
-    pre_build_commands: []
+    "pre_build_commands": [],
 
     # Same expected values as pre_build_commands
-    pre_release_commands: []
+    "pre_release_commands": [],
 
     # Same expected values as pre_build_commands
-    post_release_commands: []
+    "post_release_commands": []
+}
 
-amqp:
+amqp = {
     # host server, or '{host}:{port}'
-    host: ''
+    "host": '',
 
     # userid
-    userid: ''
+    "userid": '',
 
     # password
-    password: ''
+    "password": '',
 
     # connection timeout
-    connect_timeout: 10
+    "connect_timeout": 10,
 
     # exchange name
-    exchange_name: ''
+    "exchange_name": '',
 
     # exchange routing key
-    exchange_routing_key: 'REZ.PACKAGE.RELEASED'
+    "exchange_routing_key": 'REZ.PACKAGE.RELEASED',
 
     # message delivery mode
-    message_delivery_mode: 1
+    "message_delivery_mode": 1,
 
     # extra message attributes to be published
-    message_attributes: {}
+    "message_attributes": {}
+}
diff --git a/src/rezplugins/release_vcs/rezconfig b/src/rezplugins/release_vcs/rezconfig
deleted file mode 100644
index a0a963d90..000000000
--- a/src/rezplugins/release_vcs/rezconfig
+++ /dev/null
@@ -1,3 +0,0 @@
-git:
-    # If false, cancel a package release if there is no upstream branch.
-    allow_no_upstream: false
diff --git a/src/rezplugins/release_vcs/rezconfig.py b/src/rezplugins/release_vcs/rezconfig.py
new file mode 100644
index 000000000..411fe38a8
--- /dev/null
+++ b/src/rezplugins/release_vcs/rezconfig.py
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: Apache-2.0
+# Copyright Contributors to the Rez Project
+
+
+git = {
+    # If false, cancel a package release if there is no upstream branch.
+    "allow_no_upstream": False
+}
diff --git a/src/rezplugins/shell/rezconfig b/src/rezplugins/shell/rezconfig
deleted file mode 100644
index 392a8b655..000000000
--- a/src/rezplugins/shell/rezconfig
+++ /dev/null
@@ -1,40 +0,0 @@
-sh:
-    prompt: '>'
-    executable_fullpath: null
-
-bash:
-    prompt: '>'
-    executable_fullpath: null
-
-csh:
-    prompt: '>'
-    executable_fullpath: null
-
-tcsh:
-    prompt: '>'
-    executable_fullpath: null
-
-zsh:
-    prompt: '%'
-    executable_fullpath: null
-
-cmd:
-    prompt: '$G'
-    additional_pathext: ['.PY']
-    executable_fullpath: null
-
-powershell:
-    prompt: '> $ '
-    additional_pathext: ['.PY']
-    executable_fullpath: null
-    execution_policy: null
-
-pwsh:
-    prompt: '> $ '
-    additional_pathext: ['.PY']
-    executable_fullpath: null
-    execution_policy: null
-
-gitbash:
-    prompt: '>'
-    executable_fullpath: null
diff --git a/src/rezplugins/shell/rezconfig.py b/src/rezplugins/shell/rezconfig.py
new file mode 100644
index 000000000..549cc6605
--- /dev/null
+++ b/src/rezplugins/shell/rezconfig.py
@@ -0,0 +1,45 @@
+# SPDX-License-Identifier: Apache-2.0
+# Copyright Contributors to the Rez Project
+
+
+sh = {
+    "prompt": '>',
+    "executable_fullpath": None
+}
+bash = {
+    "prompt": '>',
+    "executable_fullpath": None
+}
+csh = {
+    "prompt": '>',
+    "executable_fullpath": None
+}
+tcsh = {
+    "prompt": '>',
+    "executable_fullpath": None
+}
+zsh = {
+    "prompt": '%',
+    "executable_fullpath": None
+}
+cmd = {
+    "prompt": '$G',
+    "additional_pathext": [".PY"],
+    "executable_fullpath": None
+}
+powershell = {
+    "prompt": '> $ ',
+    "additional_pathext": [".PY"],
+    "executable_fullpath": None,
+    "execution_policy": None
+}
+pwsh = {
+    "prompt": '> $ ',
+    "additional_pathext": [".PY"],
+    "executable_fullpath": None,
+    "execution_policy": None
+}
+gitbash = {
+    "prompt": '>',
+    "executable_fullpath": None
+}