diff --git a/scripts/mk_nuget_release.py b/scripts/mk_nuget_release.py
index 98a7c6362..1db75cd69 100644
--- a/scripts/mk_nuget_release.py
+++ b/scripts/mk_nuget_release.py
@@ -14,6 +14,10 @@ import urllib.request
 import zipfile
 import sys
 import os.path
+import shutil
+import subprocess
+import mk_util
+import mk_project
 
 data = json.loads(urllib.request.urlopen("https://api.github.com/repos/Z3Prover/z3/releases/latest").read().decode())
 
@@ -27,36 +31,83 @@ def download_installs():
     for asset in data['assets']:
         url = asset['browser_download_url']
         name = asset['name']
+        if "x64" not in name:
+            continue
         print("Downloading ", url)
         sys.stdout.flush()
         urllib.request.urlretrieve(url, "packages/%s" % name)
 
-os_names = ["ubuntu-14", "ubuntu-16", "win", "debian", "osx"]
+os_info = {"ubuntu-14" : ('so', 'ubuntu.14.04-x64'),
+           'ubuntu-16' : ('so', 'ubuntu.16.04-x64'),
+           'win' : ('dll', 'win-x64'),
+           'debian' : ('so', 'debian.8-x64') }
 
+def classify_package(f):
+    for os_name in os_info:
+        if os_name in f:
+            ext, dst = os_info[os_name]
+            return os_name, f[:-4], ext, dst
+    return None
+        
 def unpack():
-    for f in os.listdir("packages"):
-        if f.endswith("zip") and "x64" in f:
-            print(f)
-            # determine os from os_names
-            # instead of this string manipulation.
-            
-            name = os.path.splitext(f)[0]
-            os_name = name[name.find("x64")+4:]
-            os_name = os_name[:os_name.find("-")]
-            print(os_name)
-            
-            zip_ref = zipfile.ZipFile("packages/%s" % f, 'r')
-            path = "out/%s" % os_name
-            zip_ref.extract("%s/bin/libz3.so" % name)
-            
     # unzip files in packages
-    pass
+    # out
+    # +- runtimes
+    #    +- win-x64
+    #    +- ubuntu.16.04-x64
+    #    +- ubuntu.14.04-x64
+    #    +- debian.8-x64
+    # +
+    for f in os.listdir("packages"):        
+        if f.endswith("zip") and "x64" in f and classify_package(f):
+            print(f)
+            os_name, package_dir, ext, dst = classify_package(f)                        
+            zip_ref = zipfile.ZipFile("packages/%s" % f, 'r')
+            zip_ref.extract("%s/bin/libz3.%s" % (package_dir, ext), "tmp")
+            mk_dir("out/runtimes/%s" % dst)
+            shutil.move("tmp/%s/bin/libz3.%s" % (package_dir, ext), "out/runtimes/%s/." % dst)
+            if "win" in f:
+                mk_dir("out/lib/netstandard1.0/")
+                for b in ["Microsoft.Z3.dll"]:
+                    zip_ref.extract("%s/bin/%s" % (package_dir, b), "tmp")
+                    shutil.move("tmp/%s/bin/%s" % (package_dir, b), "out/lib/netstandard1.0/%s" % b)
+
+def create_nuget_spec():
+    mk_project.init_version()
+    contents = """<?xml version="1.0" encoding="utf-8"?>
+<package xmlns="http://schemas.microsoft.com/packaging/2010/07/nuspec.xsd">
+    <metadata>
+        <id>Microsoft.Z3.x64</id>
+        <version>%s</version>
+        <authors>Microsoft</authors>
+        <description>Z3 is a satisfiability modulo theories solver from Microsoft Research.</description>
+        <copyright>Copyright Microsoft Corporation. All rights reserved.</copyright>
+        <tags>smt constraint solver theorem prover</tags>
+        <iconUrl>https://raw.githubusercontent.com/Z3Prover/z3/master/package/icon.jpg</iconUrl>
+        <projectUrl>https://github.com/Z3Prover/z3</projectUrl>
+        <licenseUrl>https://raw.githubusercontent.com/Z3Prover/z3/master/LICENSE.txt</licenseUrl>
+        <repository
+            type="git"
+            url="https://github.com/Z3Prover/z3.git"
+            branch="master"
+        />
+        <requireLicenseAcceptance>true</requireLicenseAcceptance>
+        <language>en</language>
+    </metadata>
+</package>"""
+
+    with open("out/Microsoft.Z3.x64.nuspec", 'w') as f:
+        f.write(contents % mk_util.get_version_string(3))
+
+def create_nuget_package():
+    subprocess.call(["nuget", "pack"], cwd="out")
 
 def main():
     mk_dir("packages")
-#   download_installs()
-#    create_nuget_dir()
+    #download_installs()
     unpack()
-#    create_nuget_package()
-    
+    create_nuget_spec()
+    create_nuget_package()
+
+
 main()
diff --git a/scripts/mk_project.py b/scripts/mk_project.py
index 5bd96c0fc..e70a094a0 100644
--- a/scripts/mk_project.py
+++ b/scripts/mk_project.py
@@ -7,9 +7,12 @@
 ############################################
 from mk_util import *
 
+def init_version():
+    set_version(4, 8, 3, 0)
+    
 # Z3 Project definition
 def init_project_def():
-    set_version(4, 8, 3, 0)
+    init_version()
     add_lib('util', [], includes2install = ['z3_version.h'])
     add_lib('polynomial', ['util'], 'math/polynomial')
     add_lib('sat', ['util'])