diff --git a/.github/workflows/check-same-version.yml b/.github/workflows/check-same-version.yml
index 37e198d..385a82d 100644
--- a/.github/workflows/check-same-version.yml
+++ b/.github/workflows/check-same-version.yml
@@ -22,11 +22,11 @@ jobs:
       - name: Install Python
         uses: actions/setup-python@v5
         with:
-          python-version: ">=3.12" # required by same-version
-          cache: 'pip' # optional
+          python-version: ">=3.10" # required by same-version
+          cache: 'pip' # optional and only works for Python projects
 
       - name: Run same-version
-        uses: willynilly/same-version@v4.0.0
+        uses: willynilly/same-version@v5.0.0
         with:
           fail_for_missing_file: false
           check_github_event: true
@@ -46,6 +46,7 @@ jobs:
           check_r_description: false
           check_composer_json: false
           check_pom_xml: false
+          check_nuspec: false
           check_cargo_toml: false
           check_ro_crate_metadata_json: false
           check_py_version_assignment: false
diff --git a/CITATION.cff b/CITATION.cff
index 460f7ca..e2e183f 100644
--- a/CITATION.cff
+++ b/CITATION.cff
@@ -34,7 +34,7 @@ keywords:
   - metadata
   - harmonization
 license: Apache-2.0
-version: "4.0.0"
+version: "5.0.0"
 date-released: "2025-06-10"
 references:
   - title: Citation File Format
diff --git a/README.md b/README.md
index e92e12b..e8f20df 100644
--- a/README.md
+++ b/README.md
@@ -64,11 +64,12 @@ This workflow runs after the tag or release exists and can report problems, but
 - `composer.json` (PHP)
 - `Cargo.toml` (Rust)
 - `pom.xml` (Java)
+- `.nuspec` (.NET/C#/NuGet)
 - `DESCRIPTION` (R)
 - `ro-crate-metadata.json` (RO-Crate)
 
 
-✅ Cross-language support (e.g., Python, R, JS/TypeScript, Java, Rust, PHP)
+✅ Cross-language support (e.g., Python, R, JS/TypeScript, Java, Rust, PHP, C#)
 
 ✅ Cross-standard support for FAIR and Open Science metadata (e.g., CFF, CodeMeta, RO-Crate, Zenodo)
 
@@ -92,22 +93,24 @@ This workflow runs after the tag or release exists and can report problems, but
 
 These files are currently supported out-of-the-box:
 
-| File             | Parser used |
-|------------------|-------------|
+| File             | Initial Version Format (translates to PEP 440 for comparison) |
+|------------------|-------------------|
 | `CITATION.cff`   | PEP 440 |
 | `pyproject.toml` | PEP 440 |
 | `setup.py`       | PEP 440 |
-| `package.json`   | Strict SemVer (converted from canonical PEP 440 tag) |
+| `package.json`   | Strict SemVer |
 | `codemeta.json`  | PEP 440 |
 | `.zenodo.json`   | PEP 440 |
 | `composer.json`   | PEP 440 |
 | `Cargo.toml`   | PEP 440 |
 | `pom.xml`   | PEP 440 |
+| `.nuspec`   | Strict SemVer |
 | R `DESCRIPTION` file   | PEP 440 |
 | Python file with `__version__` assignment   | PEP 440 |
 | `ro-crate-metadata.json` | PEP 440 |
 
-
+Note SemVer allows arbitrary pre-releases while PEP 440 only allows 3 kinds (a, b, rc).
+During conversion, 
 
 ---
 
@@ -146,6 +149,8 @@ These files are currently supported out-of-the-box:
 | `--r-description-path`       | `r_description_path`                   | Path to R `DESCRIPTION` file         | No        | `DESCRIPTION`  |
 | `--check-pom-xml`      | `check_pom_xml`                  | Check `pom.xml`? (`true/false`)  | No  | `true`            |
 | `--pom-xml-path`       | `pom_xml_path`                   | Path to `pom.xml`         | No        | `pom.xml`  |
+| `--check-nuspec`      | `check_nu_spec`                  | Check `.nuspec`? (`true/false`)  | No  | `true`            |
+| `--nuspec-path`       | `nuspec_path`                   | Path to `.nuspec`         | No        | `.nuspec`  |
 
 
 
@@ -200,11 +205,10 @@ jobs:
       - name: Install Python
         uses: actions/setup-python@v5
         with:
-          python-version: ">=3.12"
-          cache: 'pip'
+          python-version: ">=3.10"
 
       - name: Run same-version
-        uses: willynilly/same-version@v4.0.0
+        uses: willynilly/same-version@v5.0.0
         with:
           fail_for_missing_file: false
           check_github_event: true
@@ -220,6 +224,7 @@ jobs:
           check_cargo_toml: false
           check_py_version_assignment: false
           check_pom_xml: false
+          check_nuspec: false
           check_composer_json: false
           check_ro_crate_metadata_json: false
 ```
@@ -249,11 +254,10 @@ jobs:
       - name: Install Python
         uses: actions/setup-python@v5
         with:
-          python-version: ">=3.12"
-          cache: 'pip'
+          python-version: ">=3.10"
 
       - name: Run same-version
-        uses: willynilly/same-version@v4.0.0
+        uses: willynilly/same-version@v5.0.0
         with:
           fail_for_missing_file: false
           check_github_event: true
@@ -269,6 +273,7 @@ jobs:
           check_cargo_toml: false
           check_py_version_assignment: false
           check_pom_xml: false
+          check_nuspec: false
           check_composer_json: false
           check_ro_crate_metadata_json: false
 ```
@@ -289,7 +294,7 @@ Add to your `.pre-commit-config.yaml`:
 ```yaml
 repos:
   - repo: https://github.com/willynilly/same-version
-    rev: v4.0.0  # Use latest tag
+    rev: v5.0.0  # Use latest tag
     hooks:
       - id: same-version
         stages: [pre-commit, pre-push]
@@ -357,7 +362,7 @@ To set up your development environment:
 ```bash
 git clone https://github.com/willynilly/same-version.git
 cd same-version
-pip install -e .
+pip install -e .[testing,dev]
 pre-commit install -t pre-commit -t pre-push
 pre-commit run --all-files
 ```
diff --git a/example.pre-commit-config.yaml b/example.pre-commit-config.yaml
index 59ab8e6..aeacc5c 100644
--- a/example.pre-commit-config.yaml
+++ b/example.pre-commit-config.yaml
@@ -1,6 +1,6 @@
 repos:
   - repo: https://github.com/willynilly/same-version
-    rev: v4.0.0  # Use latest tag
+    rev: v5.0.0  # Use latest tag
     hooks:
       - id: same-version
         stages: [pre-commit, pre-push]
diff --git a/pyproject.toml b/pyproject.toml
index 7a5590e..38ea286 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,12 +4,11 @@ build-backend = "hatchling.build"
 
 [project]
 name = "same-version"
-version = "4.0.0"
+version = "5.0.0"
 description = "Automatically ensures your software version metadata is consistent across key project files."
 readme = "README.md"
-requires-python = ">=3.12"
+requires-python = ">=3.10"
 license = "Apache-2.0"
-license-files = ["LICEN[CS]E*"]
 keywords = ["open science", "FAIR", "version", "software quality", "DevOps", "CI/CD", "GitHub Action", "pyproject.toml", "package.json", "setup.py", "codemeta.json", ".zenodo.json", "Zenodo", "CodeMeta", "CITATION.cff", "CFF", "citation", "metadata", "harmonization"]
 authors = [
   { name = "Will Riley", email = "wanderingwill@gmail.com" },
@@ -31,7 +30,7 @@ classifiers = [
     "Topic :: Software Development",
     "Topic :: Utilities"
 ]
-dependencies = ["pyyaml>=6.0.2", "tomli>=2.2.1", "packaging>=25.0", "semver>=3.0.4"]
+dependencies = ["pyyaml>=6.0.2", "tomli>=2.2.1", "verple>=1.0.0"]
 
 [project.urls]
 Homepage = "https://github.com/willynilly/same-version"
@@ -45,6 +44,7 @@ testing = [
 ]
 dev = [
     "ruff>=0.11.12",
+    "pre-commit>=4.2.0"
 ]
 
 [tool.pytest.ini_options]
@@ -54,6 +54,7 @@ pythonpath = [
 
 [tool.hatch.build]
 include = ["src/same_version/**", "CITATION.cff"]
+license-files = ["LICEN[CS]E*"]
 
 [tool.hatch.build.targets.wheel]
 packages = ["src/same_version"]
diff --git a/src/same_version/checkers/checker.py b/src/same_version/checkers/checker.py
index 2467520..cd5938e 100644
--- a/src/same_version/checkers/checker.py
+++ b/src/same_version/checkers/checker.py
@@ -1,10 +1,9 @@
 import logging
 from argparse import Namespace
 
-import packaging.version
+from verple.verple import Verple
 
 from same_version.extractors.extractor import Extractor
-from same_version.utils import parse_version_pep440
 
 logger = logging.getLogger(__name__)
 
@@ -14,18 +13,23 @@ def __init__(self, extractor: Extractor, cli_args: Namespace):
         self.extractor = extractor        
         self.cli_args = cli_args
         self._extracted_version: str | None = self.extractor.extract_version()
-
-    def create_pep440_version(self, version_str: str | None) -> packaging.version.Version | None:
-        version_pep440 : packaging.version.Version | None = parse_version_pep440(version_str)
-        return version_pep440
+        self._verple_version: Verple | None = self.create_verple_version(self._extracted_version)
+    
+    def create_verple_version(self, version_str: str | None) -> Verple | None:
+        if version_str is None:
+            return None
+        try:
+            return Verple.parse(version_str)
+        except ValueError:
+            return None
     
     @property
     def target_version_str(self) -> str | None:
         return self._extracted_version
     
     @property
-    def target_version_pep440(self) -> packaging.version.Version | None:
-        return self.create_pep440_version(version_str=self.target_version_str)
+    def target_version(self) -> Verple | None:
+        return self._verple_version
     
     @property
     def target_exists(self) -> bool:
@@ -40,12 +44,11 @@ def target_cli_parameter_name(self) -> str | None:
         return self.extractor.target_cli_parameter_name
     
     def check(self, base_version_str: str | None) -> bool:
-        if not base_version_str:
+        if base_version_str is None:
                 return True
-        base_version_pep440 = self.create_pep440_version(version_str=base_version_str)
+        base_version: Verple | None = self.create_verple_version(version_str=base_version_str)
         if self.target_exists:
-
-            if base_version_pep440 != self.target_version_pep440:
+            if base_version != self.target_version:
                 self._log_version_mismatch(base_version_str=base_version_str)
                 return False
             else:
diff --git a/src/same_version/checkers/nuspec_checker.py b/src/same_version/checkers/nuspec_checker.py
new file mode 100644
index 0000000..6e50b12
--- /dev/null
+++ b/src/same_version/checkers/nuspec_checker.py
@@ -0,0 +1,13 @@
+import logging
+from argparse import Namespace
+
+from same_version.checkers.file_checker import FileChecker
+from same_version.extractors.nuspec_extractor import NuspecExtractor
+
+logger = logging.getLogger(__name__)
+
+
+class NuspecChecker(FileChecker):
+
+    def __init__(self, extractor: NuspecExtractor, cli_args: Namespace):
+        super().__init__(extractor=extractor, cli_args=cli_args)  
\ No newline at end of file
diff --git a/src/same_version/checkers/package_json_checker.py b/src/same_version/checkers/package_json_checker.py
index 7d1c156..2366827 100644
--- a/src/same_version/checkers/package_json_checker.py
+++ b/src/same_version/checkers/package_json_checker.py
@@ -1,40 +1,12 @@
 import logging
+from argparse import Namespace
 
 from same_version.checkers.file_checker import FileChecker
-from same_version.utils import parse_version_semver
+from same_version.extractors.package_json_extractor import PackageJsonExtractor
 
 logger = logging.getLogger(__name__)
 
 class PackageJsonChecker(FileChecker):
-
-    def check(self, base_version_str: str | None) -> bool:
-        if base_version_str is None:
-            return True
-        base_version_pep440 = self.create_pep440_version(version_str=base_version_str)
-        if base_version_pep440 is None:
-            return True
-        
-        if self.target_exists:
-            target_version_str = self.target_version_str
-            target_name = self.target_name
-
-            try:
-                base_version_semver_str: str = f"{base_version_pep440.major}.{base_version_pep440.minor}.{base_version_pep440.micro}"
-                if base_version_pep440.is_prerelease and base_version_pep440.pre is not None:
-                    base_version_semver_str += f"-{base_version_pep440.pre[0]}.{base_version_pep440.pre[1]}"
-
-                base_version_semver = parse_version_semver(base_version_semver_str)
-                target_version_semver = parse_version_semver(target_version_str)
-
-                if base_version_semver != target_version_semver:
-                    logger.error(f"❌ Version mismatch: {target_name} {target_version_str} != base version {base_version_str}")
-                    return False
-                else:
-                    return True
-            
-            except Exception as e:
-                logger.error(f"❌ Parse error: Could not parse tag version as SemVer for {self.target_name}: {e}")
-                return False
-        else:
-            self._log_missing_target()
-            return False
+    
+    def __init__(self, extractor: PackageJsonExtractor, cli_args: Namespace):
+        super().__init__(extractor=extractor, cli_args=cli_args)  
diff --git a/src/same_version/extractors/extractor.py b/src/same_version/extractors/extractor.py
index 4a22c47..20ca8a0 100644
--- a/src/same_version/extractors/extractor.py
+++ b/src/same_version/extractors/extractor.py
@@ -7,6 +7,9 @@ class Extractor:
     def __init__(self):
         pass
 
+    def _should_have_version_in_data(self, data: dict) -> bool:
+        return True
+
     def _get_data(self) -> dict:
         raise NotImplementedError()
     
@@ -15,6 +18,9 @@ def _get_version_from_data(self, data: dict) -> str | None:
     
     def _log_missing_version_error(self, data: dict):
         logger.error(f"❌ {self.target_name} missing version metadata")
+    
+    def _log_should_not_have_version_error(self, version: str, data: dict):
+        logger.error(f"❌ {self.target_name} should not have version metadata, but has version: {version}")
 
     def _log_found_version_info(self, version: str, data: dict):
         logger.info(f"📖 {self.target_name} version: {version}")
@@ -23,12 +29,15 @@ def extract_version(self) -> str | None:
         data: dict = self._get_data()
         version = self._get_version_from_data(data=data)
         if version is None:
-            if self.target_exists:
+            if self.target_exists and self._should_have_version_in_data(data=data):
                 # only print this error if the target exists
                 self._log_missing_version_error(data=data)
             return None
-        self._log_found_version_info(version=version, data=data)
-        return version
+        elif not self._should_have_version_in_data(data=data):
+            self._log_should_not_have_version_error(version=version, data=data)
+        else:
+            self._log_found_version_info(version=version, data=data)
+            return version
     
     @property
     def target_exists(self) -> bool:
diff --git a/src/same_version/extractors/github_event_extractor.py b/src/same_version/extractors/github_event_extractor.py
index 8b95f56..c8d6ca9 100644
--- a/src/same_version/extractors/github_event_extractor.py
+++ b/src/same_version/extractors/github_event_extractor.py
@@ -28,6 +28,13 @@ def target_name(self) -> str | None:
     def target_cli_parameter_name(self) -> str | None:
         return '--github-event-name'
 
+    def _should_have_version_in_data(self, data: dict):
+        # only the push and release have version metadata
+        # the pull request does not and should not.
+        event_name: str | None = data.get('github_event_name', None)
+        return event_name == 'push' or event_name == 'release'
+
+
     def _get_data(self) -> dict[str, str | None]:
         return self._data
     
@@ -55,7 +62,7 @@ def _get_version_from_data(self, data: dict) -> str | None:
             logger.info(f"📦 Detected GitHub release tag version: {version}")
             return version
         elif event_name == 'pull_request':
-            logger.info("📦 Detected GitHub pull request")
+            logger.info("📦 Detected GitHub pull request. No version expected.")
             return None
         else:
             logger.error(f"❌ Unsupported GitHub event: {event_name}")
diff --git a/src/same_version/extractors/nuspec_extractor.py b/src/same_version/extractors/nuspec_extractor.py
new file mode 100644
index 0000000..bce7c56
--- /dev/null
+++ b/src/same_version/extractors/nuspec_extractor.py
@@ -0,0 +1,38 @@
+import xml.etree.ElementTree as ET
+from argparse import Namespace
+
+from same_version.extractors.xml_extractor import XmlExtractor
+
+
+class NuspecExtractor(XmlExtractor):
+    
+    def __init__(self, cli_args: Namespace):
+        target_cli_parameter_name: str = '--nuspec-path'
+        default_target_name: str = ".nuspec"
+        super().__init__(
+            target_file_path=self._create_target_file_path_from_cli_arg(cli_args=cli_args, cli_arg_parameter=target_cli_parameter_name), 
+            default_target_name=default_target_name, 
+            target_cli_parameter_name=target_cli_parameter_name
+        )
+
+    def _get_version_from_data(self, data: dict) -> str | None:
+        version: str | None = None
+        tree: ET.ElementTree[ET.Element[str]] | None = data.get('tree', None)
+        if tree is not None:
+
+            try:
+                root = tree.getroot()
+
+                # XML structure: <package><metadata><version>...</version>
+                # The {*} is used for optional namespaces that some tools prepend
+                metadata = root.find('metadata') or root.find('{*}metadata')
+
+                if metadata is not None:
+                    version_elem = metadata.find('version') or metadata.find('{*}version')
+                    if version_elem is not None and version_elem.text:
+                        version = version_elem.text.strip()
+
+            except Exception:
+                version = None
+
+        return version
diff --git a/src/same_version/main.py b/src/same_version/main.py
index f77baeb..fd49148 100644
--- a/src/same_version/main.py
+++ b/src/same_version/main.py
@@ -10,6 +10,7 @@
 from same_version.checkers.codemeta_json_checker import CodeMetaJsonChecker
 from same_version.checkers.composer_json_checker import ComposerJsonChecker
 from same_version.checkers.github_event_checker import GitHubEventChecker
+from same_version.checkers.nuspec_checker import NuspecChecker
 from same_version.checkers.package_json_checker import PackageJsonChecker
 from same_version.checkers.pom_xml_checker import PomXmlChecker
 from same_version.checkers.py_version_assignment_checker import (
@@ -28,6 +29,7 @@
 from same_version.extractors.codemeta_json_extractor import CodeMetaJsonExtractor
 from same_version.extractors.composer_json_extractor import ComposerJsonExtractor
 from same_version.extractors.github_event_extractor import GitHubEventExtractor
+from same_version.extractors.nuspec_extractor import NuspecExtractor
 from same_version.extractors.package_json_extractor import PackageJsonExtractor
 from same_version.extractors.pom_xml_extractor import PomXmlExtractor
 from same_version.extractors.py_version_assignment_extractor import (
@@ -72,6 +74,9 @@ def parse_args() -> argparse.Namespace:
     parser.add_argument('--check-pom-xml', default=True, required=False, help='Check pom.xml? (true/false)')
     parser.add_argument('--pom-xml-path', default='pom.xml', required=False, help='Path to pom.xml')
     
+    parser.add_argument('--check-nuspec', default=True, required=False, help='Check .nuspec? (true/false)')
+    parser.add_argument('--nuspec-path', default='.nuspec', required=False, help='Path to .nuspec')
+    
     parser.add_argument('--check-cargo-toml', default=True, required=False, help='Check Cargo.toml? (true/false)')
     parser.add_argument('--cargo-toml-path', default='Cargo.toml', required=False, help='Path to Cargo.toml')
 
@@ -156,6 +161,12 @@ def main():
         pom_xml_checker: PomXmlChecker = PomXmlChecker(extractor=pom_xml_extractor, cli_args=cli_args)
         checkers.append(pom_xml_checker)
 
+    # .nuspec
+    if str(getattr(cli_args, 'check_nuspec', '') or '').lower() == 'true':
+        nuspec_extractor: NuspecExtractor = NuspecExtractor(cli_args=cli_args)
+        nuspec_checker: NuspecChecker = NuspecChecker(extractor=nuspec_extractor, cli_args=cli_args)
+        checkers.append(nuspec_checker)
+
     # R DESCRIPTION file
     if str(getattr(cli_args, 'check_r_description', '') or '').lower() == 'true':
         r_description_extractor: RDescriptionExtractor = RDescriptionExtractor(cli_args=cli_args)
diff --git a/src/same_version/utils.py b/src/same_version/utils.py
deleted file mode 100644
index 0e33d17..0000000
--- a/src/same_version/utils.py
+++ /dev/null
@@ -1,14 +0,0 @@
-
-import packaging.version
-import semver
-
-
-def parse_version_pep440(v: str | None) -> packaging.version.Version | None:
-    if v is None:
-        return None
-    return packaging.version.Version(v)
-
-def parse_version_semver(v: str | None) -> semver.Version | None:
-    if v is None:
-        return None
-    return semver.Version.parse(v)
\ No newline at end of file