diff --git a/scripts/build_runtime.py b/scripts/build_runtime.py
index e9b48f4..64c6012 100644
--- a/scripts/build_runtime.py
+++ b/scripts/build_runtime.py
@@ -3,7 +3,12 @@ import os
 import platform
 import subprocess
 
-from utils import pushd, removeall, shellish
+import checksum
+from log import *
+from utils import pushd, removeall
+
+
+ANGLE_VERSION = "2023-07-05"
 
 
 def attach_build_runtime(subparsers):
@@ -13,24 +18,12 @@ def attach_build_runtime(subparsers):
 
 
 def build_runtime(args):
-    try:
-        subprocess.run(["clang", "-v"], stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
-    except FileNotFoundError:
-        print("ERROR: clang was not found on your system.")
-        if platform.system() == "Windows":
-            print("We recommend installing clang via the Visual Studio installer.")
-            # TODO(ben): Link to the Visual Studio download page (I have no internet right now)
-        elif platform.system() == "Darwin":
-            print("Run the following to install it:")
-            print()
-            print("  brew install llvm")
-            print()
-        exit(1)
-
-    # TODO(ben): Check for xcode command line tools
+    ensure_programs()
+    ensure_angle()
 
     build_milepost("lib", args.release)
 
+
 def build_milepost(target, release):
     print("Building milepost...")
     with pushd("milepost"):
@@ -42,7 +35,8 @@ def build_milepost(target, release):
             if platform.system() == "Darwin":
                 build_milepost_lib_mac(release)
             else:
-                print(f"ERROR: can't build milepost for unknown platform '{platform.system()}'")
+                log_error(f"can't build milepost for unknown platform '{platform.system()}'")
+                exit(1)
         elif target == "test":
             with pushd("examples/test_app"):
                 # TODO?
@@ -50,9 +44,10 @@ def build_milepost(target, release):
         elif target == "clean":
             removeall("bin")
         else:
-            print(f"ERROR: unrecognized milepost target '{target}'")
+            log_error(f"unrecognized milepost target '{target}'")
             exit(1)
 
+
 def build_milepost_lib_mac(release):
     sdk_dir = "/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk"
 
@@ -123,3 +118,59 @@ def build_milepost_lib_mac(release):
         "-id", "@rpath/libmilepost.dylib",
         "bin/libmilepost.dylib",
     ], check=True)
+
+
+def ensure_programs():
+    try:
+        subprocess.run(["clang", "-v"], stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
+    except FileNotFoundError:
+        msg = log_error("clang was not found on your system.")
+        if platform.system() == "Windows":
+            msg.more("We recommend installing clang via the Visual Studio installer.")
+            # TODO(ben): Link to the Visual Studio download page (I have no internet right now)
+        elif platform.system() == "Darwin":
+            msg.more("Run the following to install it:")
+            msg.more()
+            msg.more("  brew install llvm")
+            msg.more()
+        exit(1)
+    # TODO(ben): Check for xcode command line tools
+
+
+def ensure_angle():
+    checkfiles = None
+    if platform.system() == "Windows":
+        checkfiles = [
+            ["libEGL-win", "milepost/lib/libEGL.dll"],
+            ["libGLESv2-win", "milepost/lib/libGLESv2.dll"],
+        ]
+    elif platform.system() == "Darwin":
+        # TODO(ben): Do we need specific builds of ANGLE for each macOS version?
+        if platform.machine() == "arm64":
+            checkfiles = [
+                ["libEGL-mac-arm64", "milepost/lib/libEGL.dylib"],
+                ["libGLESv2-mac-arm64", "milepost/lib/libGLESv2.dylib"],
+            ]
+        else:
+            checkfiles = [
+                ["libEGL-mac-x64", "milepost/lib/libEGL.dylib"],
+                ["libGLESv2-mac-x64", "milepost/lib/libGLESv2.dylib"],
+            ]
+
+    if checkfiles is None:
+        log_warning("could not verify if the correct version of ANGLE is present; the build will probably fail.")
+        return
+
+    angle_exists = True
+    for file in checkfiles:
+        key = file[0]
+        filepath = file[1]
+        if not os.path.isfile(filepath):
+            angle_exists = False
+            break
+        if not checksum.checkfile(key, filepath):
+            log_error("wrong version of ANGLE libraries installed")
+            exit(1)
+
+    if not angle_exists:
+        pass
diff --git a/scripts/checksum.py b/scripts/checksum.py
new file mode 100644
index 0000000..226fbc8
--- /dev/null
+++ b/scripts/checksum.py
@@ -0,0 +1,30 @@
+import hashlib
+import json
+
+from log import *
+
+
+def checkfile(key, filepath):
+    newsum = filesum(filepath)
+
+    sums = {}
+    with open("scripts/checksums.json", "r") as sumsfile:
+        sums = json.loads(sumsfile.read())
+    if key not in sums:
+        msg = log_warning(f"no checksum saved for {key}")
+        msg.more(f"file had checksum: {newsum}")
+        return False
+    sum = sums[key]
+
+    if sum != newsum:
+        msg = log_warning(f"checksums did not match for {filepath}:")
+        msg.more(f"expected: {sum}")
+        msg.more(f"     got: {newsum}")
+        return False
+
+    return True
+
+
+def filesum(filepath):
+    with open(filepath, "rb") as file:
+        return hashlib.sha256(file.read()).hexdigest()
diff --git a/scripts/checksums.json b/scripts/checksums.json
new file mode 100644
index 0000000..1c2126f
--- /dev/null
+++ b/scripts/checksums.json
@@ -0,0 +1,6 @@
+{
+    "libEGL-win": "3c8b22317664650deba704dd40bbd56447c579ee3a3de18a9c114449a883a36d",
+    "libGLESv2-win": "a10e0ce850a981b11d3d0f01a7efbf8ce46ac74e5fa763b5c43a80c4238da389",
+    "libEGL-mac-arm64": "227445d896047207d1dcef91a8182d886692bc470f402033a6f0831eacb82592",
+    "libGLESv2-mac-arm64": "c814948060494796cda4a3febd8652e1bbf0787a69c2f7e9afd41fc666dc91fe"
+}
diff --git a/scripts/log.py b/scripts/log.py
new file mode 100644
index 0000000..1c28dbd
--- /dev/null
+++ b/scripts/log.py
@@ -0,0 +1,80 @@
+import subprocess
+import sys
+
+
+errors = []
+warnings = []
+
+
+class Entry:
+    def __init__(self, msg):
+        self.msgs = [msg]
+
+    def more(self, *msgs):
+        if len(msgs) == 0:
+            msgs = [""]
+        for msg in msgs:
+            print(msg)
+            self.msgs.append(msg)
+
+
+def log_error(msg):
+    msg = f"ERROR: {msg}"
+    print(msg)
+    entry = Entry(msg)
+    errors.append(entry)
+    return entry
+
+
+def log_warning(msg):
+    msg = f"WARNING: {msg}"
+    print(msg)
+    entry = Entry(msg)
+    warnings.append(entry)
+    return entry
+
+
+def log_finish():
+    if len(errors) + len(warnings) == 0:
+        print("Task completed successfully.")
+        return
+
+    print()
+
+    errors_str = "1 error" if len(errors) == 1 else f"{len(errors)} errors"
+    warnings_str = "1 warning" if len(warnings) == 1 else f"{len(warnings)} warnings"
+
+    if len(errors) > 0 and len(warnings) > 0:
+        print(f"Task failed with {errors_str} and {warnings_str}:")
+        for entry in warnings:
+            print("\n".join(entry.msgs))
+        for entry in errors:
+            print("\n".join(entry.msgs))
+    elif len(errors) > 0:
+        print(f"Task failed with {errors_str}:")
+        for entry in errors:
+            print("\n".join(entry.msgs))
+    elif len(warnings) > 0:
+        print(f"Task failed with {warnings_str}:")
+        for entry in warnings:
+            print("\n".join(entry.msgs))
+
+
+def shellish(func):
+    def shellfunc(*args, **kwargs):
+        exitcode = 0
+        try:
+            func(*args, **kwargs)
+        except subprocess.CalledProcessError as err:
+            msg = log_error(f"The following command failed with code {err.returncode}:")
+            msg.more(" ".join(err.cmd))
+            exitcode = err.returncode
+        except SystemExit as err:
+            exitcode = err.code
+        except:
+            log_error(sys.exception())
+            exitcode = 1
+        finally:
+            log_finish()
+            exit(exitcode)
+    return shellfunc
diff --git a/scripts/utils.py b/scripts/utils.py
index d8ef8d8..72483dc 100644
--- a/scripts/utils.py
+++ b/scripts/utils.py
@@ -18,15 +18,3 @@ def pushd(new_dir):
 def removeall(dir):
     [os.remove(f) for f in glob.iglob("{}/*".format(dir), recursive=True)]
     os.removedirs(dir)
-
-
-def shellish(func):
-    def shellfunc(*args, **kwargs):
-        try:
-            func(*args, **kwargs)
-        except subprocess.CalledProcessError as err:
-            print()
-            print(f"ERROR (code {err.returncode}): The following command failed:")
-            print(" ".join(err.cmd))
-            exit(err.returncode)
-    return shellfunc