diff --git a/ace/.gitignore b/ace/.gitignore
index 64cefc3..28c69aa 100644
--- a/ace/.gitignore
+++ b/ace/.gitignore
@@ -1,4 +1,4 @@
 Makefile
-j-lang10
+j-lang*
 *.pyc
 __pycache__/
diff --git a/ace/cmAdapter.py b/ace/cmAdapter.py
index b1919d2..d0518c5 100755
--- a/ace/cmAdapter.py
+++ b/ace/cmAdapter.py
@@ -4,6 +4,7 @@
 import os
 import re
 import sys
+import ntpath
 import stat
 import subprocess
 import argparse
@@ -650,7 +651,7 @@ def main():
 
 
     val = 0
-    new_file = test_file  + ".cpp"
+    new_file = ntpath.basename(test_file) + ".cpp"
     new_file = os.path.join(parsed_args.target_path, new_file)
     copyfile(base_file, new_file)
 
diff --git a/ace/fuzzer.py b/ace/fuzzer.py
new file mode 100755
index 0000000..f3fabb4
--- /dev/null
+++ b/ace/fuzzer.py
@@ -0,0 +1,209 @@
+#!/usr/bin/env python3
+
+# Usage: fuzzer.py [-h] --test_file TEST_FILE --output_dir OUTPUT_DIR
+#
+# Workload Fuzzer for CrashMonkey v1.0
+
+# Optional arguments:
+#   -h, --help            show this help message and exit
+#   --test_file TEST_FILE, -t TEST_FILE
+#                         J-lang test file to use as seed for fuzzer
+#   --output_dir OUTPUT_DIR, -o OUTPUT_DIR
+#                         Directory to save the generated test files
+
+import os
+import sys
+import ntpath
+import argparse
+import itertools
+import subprocess
+from shutil import copyfile
+
+import common
+
+def log(msg, flush=False):
+    sys.stdout.write(str(msg))
+    if flush: sys.stdout.flush()
+
+def parse_jlang(filename):
+    run_starts = False
+
+    ignore = ["none"]
+    instructions = []
+
+    for line in open(filename, "r"):
+        if run_starts:
+            if not any(line.startswith(i) for i in ignore):
+                instructions.append(line.strip())
+        elif "# run" in line:
+            run_starts = True
+
+    return instructions
+
+def get_permutations(instruction):
+    parts = instruction.split()
+    perms = []
+
+    if parts[0] == "open":
+        pass
+    elif parts[0] == "opendir" or parts[0] == "mkdir":
+        pass
+    elif parts[0] == "link":
+        r = parts[:]
+        r[0] = "symlink"
+        perms.append(" ".join(r))
+    elif parts[0] == "symlink":
+        r = parts[:]
+        r[0] = "link"
+        perms.append(" ".join(r))
+    elif parts[0] == "remove" or parts[0] == "unlink":
+        pass
+    elif parts[0] == "fsetxattr":
+        pass
+    elif parts[0] == "removexattr":
+        pass
+    elif parts[0] == "truncate":
+        pass
+    elif parts[0] == "dwrite":
+        r = parts[:]
+        for replace in ['write', 'mmapwrite']:
+            r[0] = replace
+            perms.append(" ".join(r))
+    elif parts[0] == "write":
+        r = parts[:]
+        for replace in ['dwrite', 'mmapwrite']:
+            r[0] = replace
+            perms.append(" ".join(r))
+    elif parts[0] == "mmapwrite":
+        r = parts[:]
+        for replace in ['dwrite', 'write']:
+            r[0] = replace
+            perms.append(" ".join(r))
+    elif parts[0] == "fsync":
+        perms.append("sync")
+
+        perms.append("fdatasync " + parts[1])
+    elif parts[0] == "fdatasync":
+        perms.append("sync")
+        perms.append("fsync " + parts[1])
+    elif parts[0] == "sync":
+        pass
+    elif parts[0] == "rename":
+        pass
+    elif parts[0] == "rmdir":
+        pass
+    elif parts[0] == "falloc":
+        filename, mode, offset, length = parts[1:]
+
+        for mode_i in common.FallocOptions:
+            if mode != mode_i:
+                perms.append("falloc {} {} {} {}".format(filename, mode_i, offset, length))
+    elif parts[0] == "checkpoint" or parts[0] == "close":
+        pass
+    else:
+        print("Unknown instruction: {}".format(instruction))
+        sys.exit(1)
+
+    return perms
+
+def write_jlang_file(lines, filename, base_jlang):
+    copyfile(base_jlang, filename)
+
+    log("Writing to file {}\n".format(filename))
+    with open(filename, "a") as f:
+        f.write("\n# run\n")
+
+        add_newline = lambda f: f + "\n"
+        lines = list(map(add_newline, lines))
+        f.writelines(lines)
+
+def fuzz(instructions, test_file, output_dir):
+    test_name = ntpath.basename(test_file)
+    base_jlang = os.path.join(output_dir, "base-j-lang")
+    base_cm = os.path.join(output_dir, "base.cpp")
+
+    if not output_dir.endswith("/"):
+        output_dir += "/"
+
+    # Function to generate numbered filenames of the format:
+    #     <test_file>-fuzz<num>
+    num_created = 1
+    def make_name():
+        nonlocal num_created
+
+        name = "{}-fuzz{}".format(test_name, num_created)
+        num_created += 1
+        return name
+
+    # Single-operation mutation. For each operation, try all
+    # possible modifications.
+    options = [get_permutations(i) for i in instructions]
+    modified_instructions = instructions[:]
+    for i, instr in enumerate(instructions):
+        for option_i in options[i]:
+            modified_instructions[i] = option_i
+
+            # Write the list of modified instructions to a j-lang file
+            write_jlang_file(modified_instructions, make_name(), base_jlang)
+
+        modified_instructions[i] = instr
+
+    # Convert the original J-lang file using the Crashmonkey Adapter.
+    cmd = "python3 cmAdapter.py -b {} -t {} -p {}\n".format(base_cm, test_file, output_dir)
+    subprocess.call(cmd, shell=True)
+    copyfile(test_file, os.path.join(output_dir, test_name))
+
+    # Convert the generated J-lang files.
+    for i in range(1, num_created):
+        jlang_name = "{}-fuzz{}".format(test_name, i)
+
+        cmd = "python3 cmAdapter.py -b {} -t {} -p {}\n".format(
+                base_cm,
+                jlang_name,
+                output_dir)
+        subprocess.call(cmd, shell=True)
+
+        # Move J-lang file to output folder.
+        os.rename(jlang_name, os.path.join(output_dir, jlang_name))
+
+
+def build_parser():
+    parser = argparse.ArgumentParser(description='Workload Fuzzer for CrashMonkey v1.0')
+
+    parser.add_argument('--test_file', '-t',
+            required=True, help='J-lang test file to use as seed for fuzzer')
+    parser.add_argument('--output_dir', '-o',
+            required=True, help='Directory to save the generated test files')
+
+    return parser
+
+def main():
+    parsed_args = build_parser().parse_args()
+
+    # Ensure J-lang file exists
+    if not os.path.isfile(parsed_args.test_file):
+        print("{} : File not found".format(parsed_args.test_file))
+        sys.exit(1)
+
+    # Create output directory if it does not exist
+    if not os.path.isdir(parsed_args.output_dir):
+        if os.path.exists(parsed_args.output_dir):
+            print("{} already exists but is not directory".format(parsed_args.output_dir))
+            sys.exit(1)
+        os.makedirs(parsed_args.output_dir)
+
+    # Copy base J-lang file to output directory
+    cwd = os.path.dirname(os.path.realpath(__file__))
+    base_j_lang = os.path.join(cwd, "../code/tests/ace-base/base-j-lang")
+    copyfile(base_j_lang, os.path.join(parsed_args.output_dir, "base-j-lang"))
+
+    # Copy base Crashmonkey file to outpt directory
+    base_cm = os.path.join(cwd, "../code/tests/ace-base/base.cpp")
+    copyfile(base_cm, os.path.join(parsed_args.output_dir, "base.cpp"))
+
+    instructions = parse_jlang(parsed_args.test_file)
+    fuzz(instructions, parsed_args.test_file, parsed_args.output_dir)
+
+
+if __name__ == '__main__':
+    main()
diff --git a/docs/Fuzzer.md b/docs/Fuzzer.md
new file mode 100644
index 0000000..de1d11b
--- /dev/null
+++ b/docs/Fuzzer.md
@@ -0,0 +1,16 @@
+# Fuzzer
+
+### Overview
+The [ACE](Ace.md) framework also supports a fuzzer that can search the space around given J-lang workloads. Specifically, it takes high-level "J-lang" workloads as inputs and exhaustively searches the space of *single-operation modifications* around that workload. For example, given a workload with a write operation, the fuzzer will generate two additional test cases that swap the write operation and for dwrite and mmapwrite respectively. It will do this swap/generation for each operation in the test case.
+
+This fuzzer is useful for searching around longer, n-length workloads, for which exhaustively searching the space of n-length workloads with ACE is not feasible. When given a longer workload that triggers a bug, or triggered a bug at some point in time, this fuzzer may be able to find similar bugs around it.
+
+### Usage
+The fuzzer can be found [here](../ace/fuzzer.py). Running `./fuzzer.py -h` will give detailed usage instrutions. The main arguments are shown below:
+
+  *Flags:*
+
+  * `-t FILE`, `--test_file FILE` - Use the given `FILE` as the starting seed for the fuzzer.
+  * `-o DIR`, `--output_dir DIR` - Output files into `DIR`.
+
+For each generated test, the fuzzer will create a high level, J-lang file and a Crashmonkey workload (using the Crashmonkey adapter [here](../code/cmAdapter.py)) in the output directory.
diff --git a/xfsMonkey.py b/xfsMonkey.py
index 751cc7c..229755c 100755
--- a/xfsMonkey.py
+++ b/xfsMonkey.py
@@ -122,7 +122,7 @@ def main():
 			snapshot = filename.replace('.so', '') + '_' + parsed_args.fs_type
 
 			#Get full test file path
-			test_file = xfsMonkeyTestPath.replace('./build/', '') + filename
+			test_file = os.path.join(xfsMonkeyTestPath.replace('./build/', ''), filename)
 
 			#Build command to run c_harness 
 			command = ('cd build; ./c_harness -v -c -P -f '+ parsed_args.flag_dev +' -d '+