diff --git a/e2e/binary/BUILD.bazel b/e2e/binary/BUILD.bazel
index 12a2bf99e80503c8c7960482add9ac8c8c7d20e8..ede035ea54f5c456ab5ecf10210c8c69c79debe8 100644
--- a/e2e/binary/BUILD.bazel
+++ b/e2e/binary/BUILD.bazel
@@ -12,8 +12,9 @@ build_test(
 py_library(
     name = "pytest",
     srcs = [
+        "__init__.py",
         "conftest.py",
-        "diff.py",
+        "difference.py",
         "relative.py",
         "runfile.py",
         "tool.py",
diff --git a/e2e/binary/__init__.py b/e2e/binary/__init__.py
new file mode 100644
index 0000000000000000000000000000000000000000..f79c189427d55c4680385037f927f24f87a82dec
--- /dev/null
+++ b/e2e/binary/__init__.py
@@ -0,0 +1,7 @@
+from __future__ import annotations
+
+from binary.difference import Diff
+from binary.relative import Relative
+from binary.tool import Tool
+
+__all__ = ("Diff", "Tool", "Relative")
diff --git a/e2e/binary/b2sum/digest.py b/e2e/binary/b2sum/digest.py
index 987f41f859bcd6bf02184664d529d799a04ce8f0..bfe47245312de2896e10083c72c68afe90faf7b0 100644
--- a/e2e/binary/b2sum/digest.py
+++ b/e2e/binary/b2sum/digest.py
@@ -3,9 +3,7 @@ from __future__ import annotations
 from pathlib import Path
 from subprocess import run
 
-from binary.diff import Diff
-from binary.relative import Relative
-from binary.tool import Tool
+from binary import Diff, Relative, Tool
 
 
 def test_digest(tool: Tool, relative: Relative, tmp_path: Path) -> None:
diff --git a/e2e/binary/brotli/roundtrip.py b/e2e/binary/brotli/roundtrip.py
index af04d8fb261c5e28914631e0a999a2684ae03c8c..e9f67d1998d148b338e15c3366f3492dfc1c971d 100644
--- a/e2e/binary/brotli/roundtrip.py
+++ b/e2e/binary/brotli/roundtrip.py
@@ -4,9 +4,7 @@ from pathlib import Path
 from shutil import copyfileobj
 from subprocess import PIPE, Popen
 
-from binary.diff import Diff
-from binary.relative import Relative
-from binary.tool import Tool
+from binary import Diff, Relative, Tool
 
 
 def test_roundtrip(tool: Tool, relative: Relative, tmp_path: Path) -> None:
diff --git a/e2e/binary/bzip2/roundtrip.py b/e2e/binary/bzip2/roundtrip.py
index f2feaa654beba1a1815c97f29dee16004a6fc543..5ef47ea53145904318470871a1d772998eb0a8d4 100644
--- a/e2e/binary/bzip2/roundtrip.py
+++ b/e2e/binary/bzip2/roundtrip.py
@@ -4,9 +4,7 @@ from pathlib import Path
 from shutil import copyfileobj
 from subprocess import PIPE, Popen
 
-from binary.diff import Diff
-from binary.relative import Relative
-from binary.tool import Tool
+from binary import Diff, Relative, Tool
 
 
 def test_roundtrip(tool: Tool, relative: Relative, tmp_path: Path) -> None:
diff --git a/e2e/binary/cmp/BUILD.bazel b/e2e/binary/cmp/BUILD.bazel
index 02947c538a7a987cdf9ea2d4d3441cb6e0212f57..5e657eae152c7c7663598831b73f3400dc5cce2d 100644
--- a/e2e/binary/cmp/BUILD.bazel
+++ b/e2e/binary/cmp/BUILD.bazel
@@ -1,11 +1,33 @@
-load("@bazel_skylib//rules:build_test.bzl", "build_test")
+load("@rules_python_pytest//python_pytest:defs.bzl", "py_pytest_test")
+load("@bazel_skylib//rules:native_binary.bzl", "native_test")
 
-# TODO: write an _actual_ test for `cmp`
+py_pytest_test(
+    name = "text",
+    size = "small",
+    srcs = ["text.py"],
+    data = [
+        "a.txt",
+        "b.txt",
+        "expected.txt",
+        "@ape//ape:cmp",
+    ],
+    deps = [
+        "//binary:pytest",
+    ],
+)
 
-build_test(
-    name = "cmp",
+native_test(
+    name = "version",
     size = "small",
-    tags = ["stub"],
-    targets = ["@ape//ape:cmp"],
+    src = "@ape//ape:cmp",
+    args = ["--version"],
+)
+
+test_suite(
+    name = "cmp",
+    tests = [
+        ":text",
+        ":version",
+    ],
     visibility = ["//:__subpackages__"],
 )
diff --git a/e2e/binary/cmp/a.txt b/e2e/binary/cmp/a.txt
new file mode 100644
index 0000000000000000000000000000000000000000..d47fbf508c628c4e64c26511ec80caee66b35307
--- /dev/null
+++ b/e2e/binary/cmp/a.txt
@@ -0,0 +1,5 @@
+Hello, world!
+
+This is some text.
+
+This is some other text.
diff --git a/e2e/binary/cmp/b.txt b/e2e/binary/cmp/b.txt
new file mode 100644
index 0000000000000000000000000000000000000000..00a57ad52b904e6ea8b005658dbe7e0557d0beaf
--- /dev/null
+++ b/e2e/binary/cmp/b.txt
@@ -0,0 +1,8 @@
+Hello, world?
+
+This is text.
+
+
+This is some text.
+
+This is more text.
diff --git a/e2e/binary/cmp/expected.txt b/e2e/binary/cmp/expected.txt
new file mode 100644
index 0000000000000000000000000000000000000000..7c963fafd7a75cff6fb19ceea3f470c7c5be6f10
--- /dev/null
+++ b/e2e/binary/cmp/expected.txt
@@ -0,0 +1 @@
+binary/cmp/a.txt binary/cmp/b.txt differ: char 13, line 1
diff --git a/e2e/binary/cmp/text.py b/e2e/binary/cmp/text.py
new file mode 100644
index 0000000000000000000000000000000000000000..fe9e7b81bc1e93dc2618fc3b4baa388c9273a390
--- /dev/null
+++ b/e2e/binary/cmp/text.py
@@ -0,0 +1,23 @@
+from __future__ import annotations
+
+from pathlib import Path
+from subprocess import run
+from tarfile import REGTYPE, TarFile
+
+from binary import Diff, Relative, Tool
+
+
+def test_normal(tool: Tool, relative: Relative, tmp_path: Path) -> None:
+    binary = tool("cmp")
+    a = relative("a.txt")
+    b = relative("b.txt")
+    expected = relative("expected.txt")
+    output = tmp_path / "output.txt"
+
+    cmd = (binary, str(a), str(b))
+    with open(output, "w", encoding="utf-8") as stream:
+        result = run(cmd, timeout=30, stdout=stream)
+        assert 1 == result.returncode
+
+    with open(expected) as a, open(output) as b:
+        assert a.read() == b.read()
diff --git a/e2e/binary/conftest.py b/e2e/binary/conftest.py
index 4c98c8bca9adeec8bf68f24568d96ca40d1123c6..f85f9f59e437a5c7ce5d4d2ffca51c494675093c 100644
--- a/e2e/binary/conftest.py
+++ b/e2e/binary/conftest.py
@@ -2,12 +2,14 @@ from __future__ import annotations
 
 from pytest import fixture
 
-from .diff import Diff
-from .diff import repr as diff
+from .difference import Diff
+from .difference import repr as diff
 from .relative import Relative
 from .runfile import Runfile, SupportsRlocation, create
 from .tool import Tool
 
+__all__ = ("Diff", "Relative", "Tool", "Runfile")
+
 
 @fixture
 def runfiles() -> SupportsRlocation:
diff --git a/e2e/binary/diff/BUILD.bazel b/e2e/binary/diff/BUILD.bazel
index a4d660690422768205df253440db8d7f863df8f8..45fa9b5cd435f2cffe483b2c9d49902eaca4830c 100644
--- a/e2e/binary/diff/BUILD.bazel
+++ b/e2e/binary/diff/BUILD.bazel
@@ -1,11 +1,33 @@
-load("@bazel_skylib//rules:build_test.bzl", "build_test")
+load("@rules_python_pytest//python_pytest:defs.bzl", "py_pytest_test")
+load("@bazel_skylib//rules:native_binary.bzl", "native_test")
 
-# TODO: write an _actual_ test for `diff`
+py_pytest_test(
+    name = "normal",
+    size = "small",
+    srcs = ["normal.py"],
+    data = [
+        "a.txt",
+        "b.txt",
+        "expected.txt",
+        "@ape//ape:diff",
+    ],
+    deps = [
+        "//binary:pytest",
+    ],
+)
 
-build_test(
-    name = "diff",
+native_test(
+    name = "version",
     size = "small",
-    tags = ["stub"],
-    targets = ["@ape//ape:diff"],
+    src = "@ape//ape:diff",
+    args = ["--version"],
+)
+
+test_suite(
+    name = "diff",
+    tests = [
+        ":normal",
+        ":version",
+    ],
     visibility = ["//:__subpackages__"],
 )
diff --git a/e2e/binary/diff/a.txt b/e2e/binary/diff/a.txt
new file mode 100644
index 0000000000000000000000000000000000000000..d47fbf508c628c4e64c26511ec80caee66b35307
--- /dev/null
+++ b/e2e/binary/diff/a.txt
@@ -0,0 +1,5 @@
+Hello, world!
+
+This is some text.
+
+This is some other text.
diff --git a/e2e/binary/diff/b.txt b/e2e/binary/diff/b.txt
new file mode 100644
index 0000000000000000000000000000000000000000..00a57ad52b904e6ea8b005658dbe7e0557d0beaf
--- /dev/null
+++ b/e2e/binary/diff/b.txt
@@ -0,0 +1,8 @@
+Hello, world?
+
+This is text.
+
+
+This is some text.
+
+This is more text.
diff --git a/e2e/binary/diff/expected.txt b/e2e/binary/diff/expected.txt
new file mode 100644
index 0000000000000000000000000000000000000000..cb9c196e8d72211010723e95f7426f51cc5930f2
--- /dev/null
+++ b/e2e/binary/diff/expected.txt
@@ -0,0 +1,11 @@
+1c1,4
+< Hello, world!
+---
+> Hello, world?
+> 
+> This is text.
+> 
+5c8
+< This is some other text.
+---
+> This is more text.
diff --git a/e2e/binary/diff/normal.py b/e2e/binary/diff/normal.py
new file mode 100644
index 0000000000000000000000000000000000000000..cb9a993140c28317a6628da0cbbc3a700ddc788d
--- /dev/null
+++ b/e2e/binary/diff/normal.py
@@ -0,0 +1,23 @@
+from __future__ import annotations
+
+from pathlib import Path
+from subprocess import run
+from tarfile import REGTYPE, TarFile
+
+from binary import Diff, Relative, Tool
+
+
+def test_normal(tool: Tool, relative: Relative, tmp_path: Path) -> None:
+    binary = tool("diff")
+    a = relative("a.txt")
+    b = relative("b.txt")
+    expected = relative("expected.txt")
+    output = tmp_path / "output.txt"
+
+    cmd = (binary, str(a), str(b))
+    with open(output, "w", encoding="utf-8") as stream:
+        result = run(cmd, timeout=30, stdout=stream)
+        assert 1 == result.returncode
+
+    with open(expected) as a, open(output) as b:
+        assert a.read() == b.read()
diff --git a/e2e/binary/diff3/BUILD.bazel b/e2e/binary/diff3/BUILD.bazel
index 57ddfd71a14b20479eb65ad35e11f37cb932c12c..26e6bf0241232fbab6ebff9d153096e55dadfb1b 100644
--- a/e2e/binary/diff3/BUILD.bazel
+++ b/e2e/binary/diff3/BUILD.bazel
@@ -1,11 +1,35 @@
-load("@bazel_skylib//rules:build_test.bzl", "build_test")
+load("@rules_python_pytest//python_pytest:defs.bzl", "py_pytest_test")
+load("@bazel_skylib//rules:native_binary.bzl", "native_test")
 
-# TODO: write an _actual_ test for `diff3`
+py_pytest_test(
+    name = "threeway",
+    size = "small",
+    srcs = ["threeway.py"],
+    data = [
+        "a.txt",
+        "b.txt",
+        "c.txt",
+        "expected.txt",
+        "@ape//ape:diff",
+        "@ape//ape:diff3",
+    ],
+    deps = [
+        "//binary:pytest",
+    ],
+)
 
-build_test(
-    name = "diff3",
+native_test(
+    name = "version",
     size = "small",
-    tags = ["stub"],
-    targets = ["@ape//ape:diff3"],
+    src = "@ape//ape:diff3",
+    args = ["--version"],
+)
+
+test_suite(
+    name = "diff3",
+    tests = [
+        ":threeway",
+        ":version",
+    ],
     visibility = ["//:__subpackages__"],
 )
diff --git a/e2e/binary/diff3/a.txt b/e2e/binary/diff3/a.txt
new file mode 100644
index 0000000000000000000000000000000000000000..d47fbf508c628c4e64c26511ec80caee66b35307
--- /dev/null
+++ b/e2e/binary/diff3/a.txt
@@ -0,0 +1,5 @@
+Hello, world!
+
+This is some text.
+
+This is some other text.
diff --git a/e2e/binary/diff3/b.txt b/e2e/binary/diff3/b.txt
new file mode 100644
index 0000000000000000000000000000000000000000..00a57ad52b904e6ea8b005658dbe7e0557d0beaf
--- /dev/null
+++ b/e2e/binary/diff3/b.txt
@@ -0,0 +1,8 @@
+Hello, world?
+
+This is text.
+
+
+This is some text.
+
+This is more text.
diff --git a/e2e/binary/diff3/c.txt b/e2e/binary/diff3/c.txt
new file mode 100644
index 0000000000000000000000000000000000000000..13a7ca44c3f7e4555fc476a274294ab353c1d2f1
--- /dev/null
+++ b/e2e/binary/diff3/c.txt
@@ -0,0 +1,5 @@
+Hello, Earth!
+
+This is some words.
+
+This is some other text.
diff --git a/e2e/binary/diff3/expected.txt b/e2e/binary/diff3/expected.txt
new file mode 100644
index 0000000000000000000000000000000000000000..3d3ec2a1e51b34ccf4e29af97ff1493342ead17a
--- /dev/null
+++ b/e2e/binary/diff3/expected.txt
@@ -0,0 +1,23 @@
+====
+1:1c
+  Hello, world!
+2:1c
+  Hello, world?
+3:1c
+  Hello, Earth!
+====
+1:3c
+  This is some text.
+2:3c
+  This is text.
+3:3c
+  This is some words.
+====2
+1:5c
+3:5c
+  This is some other text.
+2:5,8c
+  
+  This is some text.
+  
+  This is more text.
diff --git a/e2e/binary/diff3/threeway.py b/e2e/binary/diff3/threeway.py
new file mode 100644
index 0000000000000000000000000000000000000000..252e15022e69f0d409df30290650bca8f247894c
--- /dev/null
+++ b/e2e/binary/diff3/threeway.py
@@ -0,0 +1,24 @@
+from __future__ import annotations
+
+from pathlib import Path
+from subprocess import run
+from tarfile import REGTYPE, TarFile
+
+from binary import Diff, Relative, Tool
+
+
+def test_threeway(tool: Tool, relative: Relative, tmp_path: Path) -> None:
+    binary = tool("diff3")
+    diff = tool("diff")
+    a = relative("a.txt")
+    b = relative("b.txt")
+    c = relative("c.txt")
+    expected = relative("expected.txt")
+    output = tmp_path / "output.txt"
+
+    cmd = (binary, "--diff-program", str(diff), str(a), str(b), str(c))
+    with open(output, "w", encoding="utf-8") as stream:
+        result = run(cmd, timeout=30, stdout=stream, check=True)
+
+    with open(expected) as a, open(output) as b:
+        assert a.read() == b.read()
diff --git a/e2e/binary/diff.py b/e2e/binary/difference.py
similarity index 100%
rename from e2e/binary/diff.py
rename to e2e/binary/difference.py
diff --git a/e2e/binary/gzip/roundtrip.py b/e2e/binary/gzip/roundtrip.py
index 68a3d112c098188ce95252e4a39a242925a70b0e..3e83ebb5ff3e457d342b017ec0b1747df6032f17 100644
--- a/e2e/binary/gzip/roundtrip.py
+++ b/e2e/binary/gzip/roundtrip.py
@@ -4,9 +4,7 @@ from pathlib import Path
 from shutil import copyfileobj
 from subprocess import PIPE, Popen
 
-from binary.diff import Diff
-from binary.relative import Relative
-from binary.tool import Tool
+from binary import Diff, Relative, Tool
 
 
 def test_roundtrip(tool: Tool, relative: Relative, tmp_path: Path) -> None:
diff --git a/e2e/binary/pigz/roundtrip.py b/e2e/binary/pigz/roundtrip.py
index af06be6a35f4ae55f106ba8e198a2d1f1c3483ba..a1ee0d78c4a1893c5a24ad05ceb550a38dd5e934 100644
--- a/e2e/binary/pigz/roundtrip.py
+++ b/e2e/binary/pigz/roundtrip.py
@@ -4,9 +4,7 @@ from pathlib import Path
 from shutil import copyfileobj
 from subprocess import PIPE, Popen
 
-from binary.diff import Diff
-from binary.relative import Relative
-from binary.tool import Tool
+from binary import Diff, Relative, Tool
 
 
 def test_roundtrip(tool: Tool, relative: Relative, tmp_path: Path) -> None:
diff --git a/e2e/binary/sdiff/BUILD.bazel b/e2e/binary/sdiff/BUILD.bazel
index b176048402eb928b5ea36bef031150709be0a86c..db219d129b94873b3d2fac0efee2f9d37fc4f45e 100644
--- a/e2e/binary/sdiff/BUILD.bazel
+++ b/e2e/binary/sdiff/BUILD.bazel
@@ -1,11 +1,34 @@
-load("@bazel_skylib//rules:build_test.bzl", "build_test")
+load("@rules_python_pytest//python_pytest:defs.bzl", "py_pytest_test")
+load("@bazel_skylib//rules:native_binary.bzl", "native_test")
 
-# TODO: write an _actual_ test for `sdiff`
+py_pytest_test(
+    name = "diff",
+    size = "small",
+    srcs = ["diff.py"],
+    data = [
+        "a.txt",
+        "b.txt",
+        "expected.txt",
+        "@ape//ape:diff",
+        "@ape//ape:sdiff",
+    ],
+    deps = [
+        "//binary:pytest",
+    ],
+)
 
-build_test(
-    name = "sdiff",
+native_test(
+    name = "version",
     size = "small",
-    tags = ["stub"],
-    targets = ["@ape//ape:sdiff"],
+    src = "@ape//ape:sdiff",
+    args = ["--version"],
+)
+
+test_suite(
+    name = "sdiff",
+    tests = [
+        ":diff",
+        ":version",
+    ],
     visibility = ["//:__subpackages__"],
 )
diff --git a/e2e/binary/sdiff/a.txt b/e2e/binary/sdiff/a.txt
new file mode 100644
index 0000000000000000000000000000000000000000..d47fbf508c628c4e64c26511ec80caee66b35307
--- /dev/null
+++ b/e2e/binary/sdiff/a.txt
@@ -0,0 +1,5 @@
+Hello, world!
+
+This is some text.
+
+This is some other text.
diff --git a/e2e/binary/sdiff/b.txt b/e2e/binary/sdiff/b.txt
new file mode 100644
index 0000000000000000000000000000000000000000..00a57ad52b904e6ea8b005658dbe7e0557d0beaf
--- /dev/null
+++ b/e2e/binary/sdiff/b.txt
@@ -0,0 +1,8 @@
+Hello, world?
+
+This is text.
+
+
+This is some text.
+
+This is more text.
diff --git a/e2e/binary/sdiff/diff.py b/e2e/binary/sdiff/diff.py
new file mode 100644
index 0000000000000000000000000000000000000000..0402883f1c8271105802ae94cf99c5d7159c2e74
--- /dev/null
+++ b/e2e/binary/sdiff/diff.py
@@ -0,0 +1,24 @@
+from __future__ import annotations
+
+from pathlib import Path
+from subprocess import run
+from tarfile import REGTYPE, TarFile
+
+from binary import Diff, Relative, Tool
+
+
+def test_diff(tool: Tool, relative: Relative, tmp_path: Path) -> None:
+    binary = tool("sdiff")
+    diff = tool("diff")
+    a = relative("a.txt")
+    b = relative("b.txt")
+    expected = relative("expected.txt")
+    output = tmp_path / "output.txt"
+
+    cmd = (binary, f"--diff-program={diff}", "--width=80", str(a), str(b))
+    with open(output, "w", encoding="utf-8") as stream:
+        result = run(cmd, timeout=30, stdout=stream)
+        assert 1 == result.returncode
+
+    with open(expected) as a, open(output) as b:
+        assert a.read() == b.read()
diff --git a/e2e/binary/sdiff/expected.txt b/e2e/binary/sdiff/expected.txt
new file mode 100644
index 0000000000000000000000000000000000000000..47e69649d1cd825f53355ff5f01be3ba3e18a46e
--- /dev/null
+++ b/e2e/binary/sdiff/expected.txt
@@ -0,0 +1,8 @@
+Hello, world!			      |	Hello, world?
+				      >
+				      >	This is text.
+				      >
+
+This is some text.			This is some text.
+
+This is some other text.	      |	This is more text.
diff --git a/e2e/binary/xz/roundtrip.py b/e2e/binary/xz/roundtrip.py
index dc7688636f849c1f3d8b4e9b52869cadf633f2b6..f2c3cda260bcf8a7a94eb1dee2cd5c1771f59f40 100644
--- a/e2e/binary/xz/roundtrip.py
+++ b/e2e/binary/xz/roundtrip.py
@@ -4,9 +4,7 @@ from pathlib import Path
 from shutil import copyfileobj
 from subprocess import PIPE, Popen
 
-from binary.diff import Diff
-from binary.relative import Relative
-from binary.tool import Tool
+from binary import Diff, Relative, Tool
 
 
 def test_roundtrip(tool: Tool, relative: Relative, tmp_path: Path) -> None:
diff --git a/e2e/binary/zstd/roundtrip.py b/e2e/binary/zstd/roundtrip.py
index 71d2b3e89ff9c2ca831dc9e69b16a8a8640fc0e0..3d633609d319d64338bdfe30cf98b39735b29700 100644
--- a/e2e/binary/zstd/roundtrip.py
+++ b/e2e/binary/zstd/roundtrip.py
@@ -4,9 +4,7 @@ from pathlib import Path
 from shutil import copyfileobj
 from subprocess import PIPE, Popen
 
-from binary.diff import Diff
-from binary.relative import Relative
-from binary.tool import Tool
+from binary import Diff, Relative, Tool
 
 
 def test_roundtrip(tool: Tool, relative: Relative, tmp_path: Path) -> None: