diff --git a/.gitignore b/.gitignore
index 4847247c..6ecb0de7 100644
--- a/.gitignore
+++ b/.gitignore
@@ -22,3 +22,8 @@ pip-selfcheck.json
 
 # IDEs
 .idea
+.vscode
+
+# Backup files
+*.bak
+
diff --git a/README.md b/README.md
index 297d675b..0824d7ac 100644
--- a/README.md
+++ b/README.md
@@ -35,8 +35,10 @@ Please feel free to use Tango at your school/organization. If you run into any p
 3. [Read the documentation for the VMMS API](https://github.com/autolab/Tango/wiki/Tango-VMMS-API).
 4. [Test whether Tango is set up properly and can process jobs](https://github.com/autolab/Tango/wiki/Testing-Tango).
 
-## Python 3 Upgrade
-We are in the process of porting Tango from Python 2 to Python 3. The current working branch for the update is `python3-upgrade`.
+## Python 2 Support
+Tango now runs on Python 3. However, there is a legacy branch [master-python2](https://github.com/autolab/Tango/tree/master-python2) which is a snapshot of the last Python 2 Tango commit for legacy reasons. You are strongly encouraged to upgrade to the current Python 3 version of Tango if you are still on the Python 2 version, as future enhancements and bug fixes will be focused on the current master. 
+
+We will not be backporting new features from `master` to `master-python2`.
 
 ## Contributing to Tango
 
diff --git a/clients/tango-cli.py b/clients/tango-cli.py
index ab345164..2708e0c2 100755
--- a/clients/tango-cli.py
+++ b/clients/tango-cli.py
@@ -4,6 +4,12 @@
 # tango-cli.py - Command line client for the RESTful Tango.
 #
 
+from __future__ import print_function
+from builtins import range
+from future import standard_library
+standard_library.install_aliases()
+from builtins import map
+from builtins import str
 import os
 import sys
 
@@ -12,7 +18,7 @@
 import argparse
 import requests
 import json
-import urllib
+import urllib.request, urllib.parse, urllib.error
 
 #
 #
@@ -95,35 +101,35 @@
 
 def checkKey():
     if (args.key is None):
-        print "Key must be specified with -k"
+        print("Key must be specified with -k")
         return -1
     return 0
 
 
 def checkCourselab():
     if (args.courselab is None):
-        print "Courselab must be specified with -l"
+        print("Courselab must be specified with -l")
         return -1
     return 0
 
 
 def checkFilename():
     if (args.filename is None):
-        print "Filename must be specified with --filename"
+        print("Filename must be specified with --filename")
         return -1
     return 0
 
 
 def checkInfiles():
     if (args.infiles is None):
-        print "Input files must be specified with --infiles"
+        print("Input files must be specified with --infiles")
         return -1
     return 0
 
 
 def checkDeadjobs():
     if (args.deadJobs is None):
-        print "Deadjobs must be specified with --deadJobs"
+        print("Deadjobs must be specified with --deadJobs")
         return -1
     return 0
 
@@ -139,11 +145,11 @@ def tango_open():
         response = requests.get(
             'http://%s:%d/open/%s/%s/' %
             (args.server, args.port, args.key, args.courselab))
-        print "Sent request to %s:%d/open/%s/%s/" % (args.server, args.port, args.key, args.courselab)
-        print response.content
+        print("Sent request to %s:%d/open/%s/%s/" % (args.server, args.port, args.key, args.courselab))
+        print(response.text)
 
     except Exception as err:
-        print "Failed to send request to %s:%d/open/%s/%s/" % (args.server, args.port, args.key, args.courselab)
+        print("Failed to send request to %s:%d/open/%s/%s/" % (args.server, args.port, args.key, args.courselab))
         print (str(err))
         sys.exit(0)
 
@@ -170,11 +176,11 @@ def tango_upload():
             data=f.read(),
             headers=header)
         f.close()
-        print "Sent request to %s:%d/upload/%s/%s/ filename=%s" % (args.server, args.port, args.key, args.courselab, args.filename)
-        print response.content
+        print("Sent request to %s:%d/upload/%s/%s/ filename=%s" % (args.server, args.port, args.key, args.courselab, args.filename))
+        print(response.text)
 
     except Exception as err:
-        print "Failed to send request to %s:%d/upload/%s/%s/ filename=%s" % (args.server, args.port, args.key, args.courselab, args.filename)
+        print("Failed to send request to %s:%d/upload/%s/%s/ filename=%s" % (args.server, args.port, args.key, args.courselab, args.filename))
         print (str(err))
         sys.exit(0)
 
@@ -208,11 +214,11 @@ def tango_addJob():
              args.key,
              args.courselab),
             data=json.dumps(requestObj))
-        print "Sent request to %s:%d/addJob/%s/%s/ \t jobObj=%s" % (args.server, args.port, args.key, args.courselab, json.dumps(requestObj))
-        print response.content
+        print("Sent request to %s:%d/addJob/%s/%s/ \t jobObj=%s" % (args.server, args.port, args.key, args.courselab, json.dumps(requestObj)))
+        print(response.text)
 
     except Exception as err:
-        print "Failed to send request to %s:%d/addJob/%s/%s/ \t jobObj=%s" % (args.server, args.port, args.key, args.courselab, json.dumps(requestObj))
+        print("Failed to send request to %s:%d/addJob/%s/%s/ \t jobObj=%s" % (args.server, args.port, args.key, args.courselab, json.dumps(requestObj)))
         print (str(err))
         sys.exit(0)
 
@@ -231,13 +237,13 @@ def tango_poll():
              args.port,
              args.key,
              args.courselab,
-             urllib.quote(
+             urllib.parse.quote(
                  args.outputFile)))
-        print "Sent request to %s:%d/poll/%s/%s/%s/" % (args.server, args.port, args.key, args.courselab, urllib.quote(args.outputFile))
-        print response.content
+        print("Sent request to %s:%d/poll/%s/%s/%s/" % (args.server, args.port, args.key, args.courselab, urllib.parse.quote(args.outputFile)))
+        print(response.text)
 
     except Exception as err:
-        print "Failed to send request to %s:%d/poll/%s/%s/%s/" % (args.server, args.port, args.key, args.courselab, urllib.quote(args.outputFile))
+        print("Failed to send request to %s:%d/poll/%s/%s/%s/" % (args.server, args.port, args.key, args.courselab, urllib.parse.quote(args.outputFile)))
         print (str(err))
         sys.exit(0)
 
@@ -252,11 +258,11 @@ def tango_info():
 
         response = requests.get(
             'http://%s:%d/info/%s/' % (args.server, args.port, args.key))
-        print "Sent request to %s:%d/info/%s/" % (args.server, args.port, args.key)
-        print response.content
+        print("Sent request to %s:%d/info/%s/" % (args.server, args.port, args.key))
+        print(response.text)
 
     except Exception as err:
-        print "Failed to send request to %s:%d/info/%s/" % (args.server, args.port, args.key)
+        print("Failed to send request to %s:%d/info/%s/" % (args.server, args.port, args.key))
         print (str(err))
         sys.exit(0)
 
@@ -272,11 +278,11 @@ def tango_jobs():
         response = requests.get(
             'http://%s:%d/jobs/%s/%d/' %
             (args.server, args.port, args.key, args.deadJobs))
-        print "Sent request to %s:%d/jobs/%s/%d/" % (args.server, args.port, args.key, args.deadJobs)
-        print response.content
+        print("Sent request to %s:%d/jobs/%s/%d/" % (args.server, args.port, args.key, args.deadJobs))
+        print(response.text)
 
     except Exception as err:
-        print "Failed to send request to %s:%d/jobs/%s/%d/" % (args.server, args.port, args.key, args.deadJobs)
+        print("Failed to send request to %s:%d/jobs/%s/%d/" % (args.server, args.port, args.key, args.deadJobs))
         print (str(err))
         sys.exit(0)
 
@@ -291,11 +297,11 @@ def tango_pool():
 
         response = requests.get('http://%s:%d/pool/%s/%s/' %
                                 (args.server, args.port, args.key, args.image))
-        print "Sent request to %s:%d/pool/%s/%s/" % (args.server, args.port, args.key, args.image)
-        print response.content
+        print("Sent request to %s:%d/pool/%s/%s/" % (args.server, args.port, args.key, args.image))
+        print(response.text)
 
     except Exception as err:
-        print "Failed to send request to %s:%d/pool/%s/%s/" % (args.server, args.port, args.key, args.image)
+        print("Failed to send request to %s:%d/pool/%s/%s/" % (args.server, args.port, args.key, args.image))
         print (str(err))
         sys.exit(0)
 
@@ -321,11 +327,11 @@ def tango_prealloc():
              args.image,
              args.num),
             data=json.dumps(vmObj))
-        print "Sent request to %s:%d/prealloc/%s/%s/%s/ \t vmObj=%s" % (args.server, args.port, args.key, args.image, args.num, json.dumps(vmObj))
-        print response.content
+        print("Sent request to %s:%d/prealloc/%s/%s/%s/ \t vmObj=%s" % (args.server, args.port, args.key, args.image, args.num, json.dumps(vmObj)))
+        print(response.text)
 
     except Exception as err:
-        print "Failed to send request to %s:%d/prealloc/%s/%s/%s/ \t vmObj=%s" % (args.server, args.port, args.key, args.image, args.num, json.dumps(vmObj))
+        print("Failed to send request to %s:%d/prealloc/%s/%s/%s/ \t vmObj=%s" % (args.server, args.port, args.key, args.image, args.num, json.dumps(vmObj)))
         print (str(err))
         sys.exit(0)
 
@@ -343,31 +349,31 @@ def file_to_dict(file):
 
 def tango_runJob():
     if args.runJob is None:
-        print "Invalid usage: [runJob]"
+        print("Invalid usage: [runJob]")
         sys.exit(0)
 
     dir = args.runJob
     infiles = [file for file in os.listdir(
         dir) if os.path.isfile(os.path.join(dir, file))]
     files = [os.path.join(dir, file) for file in infiles]
-    args.infiles = map(file_to_dict, infiles)
+    args.infiles = list(map(file_to_dict, infiles))
 
     args.jobname += "-0"
     args.outputFile += "-0"
-    for i in xrange(1, args.numJobs + 1):
-        print "----------------------------------------- STARTING JOB " + str(i) + " -----------------------------------------"
-        print "----------- OPEN"
+    for i in range(1, args.numJobs + 1):
+        print("----------------------------------------- STARTING JOB " + str(i) + " -----------------------------------------")
+        print("----------- OPEN")
         tango_open()
-        print "----------- UPLOAD"
+        print("----------- UPLOAD")
         for file in files:
             args.filename = file
             tango_upload()
-        print "----------- ADDJOB"
+        print("----------- ADDJOB")
         length = len(str(i - 1))
         args.jobname = args.jobname[:-length] + str(i)
         args.outputFile = args.outputFile[:-length] + str(i)
         tango_addJob()
-        print "--------------------------------------------------------------------------------------------------\n"
+        print("--------------------------------------------------------------------------------------------------\n")
 
 
 def router():
@@ -403,7 +409,7 @@ def router():
 try:
     response = requests.get('http://%s:%d/' % (args.server, args.port))
 except:
-    print 'Tango not reachable on %s:%d!\n' % (args.server, args.port)
+    print('Tango not reachable on %s:%d!\n' % (args.server, args.port))
     sys.exit(0)
 
 router()
diff --git a/config.template.py b/config.template.py
index 5e62e592..bb7d3f22 100644
--- a/config.template.py
+++ b/config.template.py
@@ -2,12 +2,13 @@
 # config.py - Global configuration constants and runtime info
 #
 
+from builtins import object
 import logging, time
 
 # Config - defines
 
 
-class Config:
+class Config(object):
     #####
     # Part 1: Tango constants for developers
     #
diff --git a/jobManager.py b/jobManager.py
index 7ec31aee..5f24bc33 100644
--- a/jobManager.py
+++ b/jobManager.py
@@ -1,3 +1,4 @@
+from __future__ import print_function
 #
 # JobManager - Thread that assigns jobs to worker threads
 #
@@ -9,6 +10,10 @@
 # is launched that will handle things from here on. If anything goes
 # wrong, the job is made dead with the error.
 #
+from builtins import object
+from future import standard_library
+standard_library.install_aliases()
+from builtins import str
 import threading, logging, time, copy
 
 from datetime import datetime
@@ -20,7 +25,7 @@
 from tangoObjects import TangoQueue
 from config import Config
 
-class JobManager:
+class JobManager(object):
 
     def __init__(self, queue):
         self.daemon = True
@@ -62,9 +67,16 @@ def __manage(self):
 
             if id:
                 job = self.jobQueue.get(id)
+
+                # job could no longer exist if it was completed by someone else
+                if job == None:
+                    continue
+
                 if not job.accessKey and Config.REUSE_VMS:
                     id, vm = self.jobQueue.getNextPendingJobReuse(id)
                     job = self.jobQueue.get(id)
+                    if job == None:
+                        continue
 
                 try:
                     # Mark the job assigned
diff --git a/jobQueue.py b/jobQueue.py
index ad43e3b9..c64484a6 100644
--- a/jobQueue.py
+++ b/jobQueue.py
@@ -7,6 +7,9 @@
 # JobManager: Class that creates a thread object that looks for new
 # work on the job queue and assigns it to workers.
 #
+from builtins import range
+from builtins import object
+from builtins import str
 import threading, logging, time
 
 from datetime import datetime
@@ -28,7 +31,7 @@
 #
 
 
-class JobQueue:
+class JobQueue(object):
 
     def __init__(self, preallocator):
         self.liveJobs = TangoDictionary("liveJobs")
@@ -53,7 +56,7 @@ def _getNextID(self):
         keys = self.liveJobs.keys()
         if (str(id) in keys):
             id = -1
-            for i in xrange(1, Config.MAX_JOBID + 1):
+            for i in range(1, Config.MAX_JOBID + 1):
                 if (str(i) not in keys):
                     id = i
                     break
@@ -191,7 +194,7 @@ def getNextPendingJob(self):
         Called by JobManager when Config.REUSE_VMS==False
         """
         self.queueLock.acquire()
-        for id, job in self.liveJobs.iteritems():
+        for id, job in self.liveJobs.items():
             if job.isNotAssigned():
                 self.queueLock.release()
                 return id
@@ -203,7 +206,7 @@ def getNextPendingJobReuse(self, target_id=None):
         Called by JobManager when Config.REUSE_VMS==True
         """
         self.queueLock.acquire()
-        for id, job in self.liveJobs.iteritems():
+        for id, job in self.liveJobs.items():
             # if target_id is set, only interested in this id
             if target_id and target_id != id:
                 continue
diff --git a/preallocator.py b/preallocator.py
index 026c09f5..8eb3f190 100644
--- a/preallocator.py
+++ b/preallocator.py
@@ -1,6 +1,8 @@
 #
 # preallocator.py - maintains a pool of active virtual machines
 #
+from builtins import object
+from builtins import range
 import threading, logging, time, copy
 
 from tangoObjects import TangoDictionary, TangoQueue, TangoIntValue
@@ -17,7 +19,7 @@
 #
 
 
-class Preallocator:
+class Preallocator(object):
 
     def __init__(self, vmms):
         self.machines = TangoDictionary("machines")
diff --git a/requirements.txt b/requirements.txt
index 618987ec..57f86313 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,10 +1,9 @@
-backports.ssl-match-hostname==3.4.0.2
-boto==2.27.0
-futures==2.2.0
-plumbum==1.4.2
-pyflakes==0.8.1
-redis==2.10.3
-requests==2.2.1
-rpyc==3.3.0
-wsgiref==0.1.2
-tornado==4.1
+backports.ssl-match-hostname==3.7.0.1
+boto==2.49.0 # used only by ec2SSH.py
+plumbum==1.6.9
+pyflakes==2.1.1
+redis==3.4.1
+requests==2.23.0
+rpyc==4.1.4
+tornado==4.5.3
+future==0.18.2
diff --git a/restful-tango/server.py b/restful-tango/server.py
index 4f67e8ef..afd4e273 100755
--- a/restful-tango/server.py
+++ b/restful-tango/server.py
@@ -1,5 +1,7 @@
+from future import standard_library
+standard_library.install_aliases()
 import tornado.web
-import urllib
+import urllib.request, urllib.parse, urllib.error
 import sys
 import os
 from tempfile import NamedTemporaryFile
@@ -67,7 +69,7 @@ def prepare(self):
         """ set up the temporary file"""
         tempdir="%s/tmp" % (Config.COURSELABS,)
         if not os.path.exists(tempdir):
-           os.mkdir(tempdir, 0700)
+           os.mkdir(tempdir, 0o700)
         if os.path.exists(tempdir) and not os.path.isdir(tempdir):
            tangoREST.log("Cannot process uploads, %s is not a directory" % (tempdir,))
            return self.send_error()
@@ -104,7 +106,7 @@ class PollHandler(tornado.web.RequestHandler):
     def get(self, key, courselab, outputFile):
         """ get - Handles the get request to poll."""
         self.set_header('Content-Type', 'application/octet-stream')
-        return tangoREST.poll(key, courselab, urllib.unquote(outputFile))
+        return tangoREST.poll(key, courselab, urllib.parse.unquote(outputFile))
 
 
 class InfoHandler(tornado.web.RequestHandler):
diff --git a/restful-tango/tangoREST.py b/restful-tango/tangoREST.py
index 59d02365..2e3d581f 100644
--- a/restful-tango/tangoREST.py
+++ b/restful-tango/tangoREST.py
@@ -1,9 +1,12 @@
+from __future__ import print_function
 # tangoREST.py
 #
 # Implements open, upload, addJob, and poll to be used for the RESTful
 # interface of Tango.
 #
 
+from builtins import object
+from builtins import str
 import sys
 import os
 import inspect
@@ -22,7 +25,7 @@
 from config import Config
 
 
-class Status:
+class Status(object):
 
     def __init__(self):
         self.found_dir = self.create(0, "Found directory")
@@ -53,7 +56,7 @@ def create(self, id, msg):
         return result
 
 
-class TangoREST:
+class TangoREST(object):
 
     COURSELABS = Config.COURSELABS
     OUTPUT_FOLDER = Config.OUTPUT_FOLDER
@@ -109,7 +112,7 @@ def checkFileExists(self, directory, filename, fileMD5):
         for elem in os.listdir(directory):
             if elem == filename:
                 try:
-                    body = open("%s/%s" % (directory, elem)).read()
+                    body = open("%s/%s" % (directory, elem)).read().encode('utf-8')
                     md5hash = hashlib.md5(body).hexdigest()
                     return md5hash == fileMD5
                 except IOError:
@@ -288,6 +291,9 @@ def upload(self, key, courselab, file, tempfile, fileMD5):
                     os.unlink(tempfile)
                     return self.status.wrong_courselab
             except Exception as e:
+                exc_type, exc_obj, exc_tb = sys.exc_info()
+                fname = os.path.split(exc_tb.tb_frame.f_code.co_filename)[1]
+                print(exc_type, fname, exc_tb.tb_lineno)
                 self.log.error("upload request failed: %s" % str(e))
                 os.unlink(tempfile)
                 return self.status.create(-1, str(e))
diff --git a/tango.py b/tango.py
index 058c9930..1d2d7b56 100755
--- a/tango.py
+++ b/tango.py
@@ -34,6 +34,8 @@
 #    the pool, the preallocator creates another instance and adds it
 #    to the pool. (preallocator.py)
 
+from builtins import object
+from builtins import str
 import threading, logging, time, stat, re, os
 
 from datetime import datetime
@@ -45,7 +47,7 @@
 from config import Config
 
 
-class TangoServer:
+class TangoServer(object):
 
     """ TangoServer - Implements the API functions that the server accepts
     """
@@ -233,7 +235,7 @@ def resetTango(self, vmms):
                     self.log.warning("Killed these %s VMs on restart: %s" %
                                 (vmms_name, namelist))
 
-            for _, job in self.jobQueue.liveJobs.iteritems():
+            for _, job in self.jobQueue.liveJobs.items():
                 if not job.isNotAssigned():
                     job.makeUnassigned()
                 self.log.debug("job: %s, assigned: %s" %
diff --git a/tangoObjects.py b/tangoObjects.py
index 17e4130f..ec389a3e 100644
--- a/tangoObjects.py
+++ b/tangoObjects.py
@@ -2,9 +2,14 @@
 #
 # Implements objects used to pass state within Tango.
 #
+from builtins import range
+from builtins import object
+from future import standard_library
+standard_library.install_aliases()
+from builtins import str
 import redis
 import pickle
-import Queue
+import queue
 from config import Config
 
 redisConnection = None
@@ -19,7 +24,7 @@ def getRedisConnection():
     return redisConnection
 
 
-class InputFile():
+class InputFile(object):
 
     """
         InputFile - Stores pointer to the path on the local machine and the
@@ -35,7 +40,7 @@ def __repr__(self):
                 self.destFile)
 
 
-class TangoMachine():
+class TangoMachine(object):
 
     """
         TangoMachine - A description of the Autograding Virtual Machine
@@ -62,7 +67,7 @@ def __repr__(self):
         return "TangoMachine(image: %s, vmms: %s)" % (self.image, self.vmms)
 
 
-class TangoJob():
+class TangoJob(object):
 
     """
         TangoJob - A job that is to be run on a TangoMachine
@@ -156,7 +161,7 @@ def TangoIntValue(object_name, obj):
         return TangoNativeIntValue(object_name, obj)
 
 
-class TangoRemoteIntValue():
+class TangoRemoteIntValue(object):
 
     def __init__(self, name, value, namespace="intvalue"):
         """The default connection parameters are: host='localhost', port=6379, db=0"""
@@ -176,7 +181,7 @@ def set(self, val):
         return self.__db.set(self.key, val)
 
 
-class TangoNativeIntValue():
+class TangoNativeIntValue(object):
 
     def __init__(self, name, value, namespace="intvalue"):
         self.key = '%s:%s' % (namespace, name)
@@ -198,10 +203,10 @@ def TangoQueue(object_name):
     if Config.USE_REDIS:
         return TangoRemoteQueue(object_name)
     else:
-        return Queue.Queue()
+        return queue.Queue()
 
 
-class TangoRemoteQueue():
+class TangoRemoteQueue(object):
 
     """Simple Queue with Redis Backend"""
 
@@ -263,7 +268,7 @@ def TangoDictionary(object_name):
         return TangoNativeDictionary()
 
 
-class TangoRemoteDictionary():
+class TangoRemoteDictionary(object):
 
     def __init__(self, object_name):
         self.r = getRedisConnection()
@@ -279,7 +284,7 @@ def set(self, id, obj):
         return str(id)
 
     def get(self, id):
-        if str(id) in self.r.hkeys(self.hash_name):
+        if self.r.hexists(self.hash_name, str(id)):
             unpickled_obj = self.r.hget(self.hash_name, str(id))
             obj = pickle.loads(unpickled_obj)
             return obj
@@ -287,7 +292,8 @@ def get(self, id):
             return None
 
     def keys(self):
-        return self.r.hkeys(self.hash_name)
+        keys = map(lambda key : key.decode(), self.r.hkeys(self.hash_name))
+        return list(keys)
 
     def values(self):
         vals = self.r.hvals(self.hash_name)
@@ -304,11 +310,11 @@ def _clean(self):
         # only for testing
         self.r.delete(self.hash_name)
 
-    def iteritems(self):
-        return iter([(i, self.get(i)) for i in xrange(1,Config.MAX_JOBID+1)
+    def items(self):
+        return iter([(i, self.get(i)) for i in range(1,Config.MAX_JOBID+1)
                 if self.get(i) != None])
 
-class TangoNativeDictionary():
+class TangoNativeDictionary(object):
 
     def __init__(self):
         self.dict = {}
@@ -317,23 +323,23 @@ def set(self, id, obj):
         self.dict[str(id)] = obj
 
     def get(self, id):
-        if str(id) in self.dict.keys():
+        if str(id) in self.dict:
             return self.dict[str(id)]
         else:
             return None
 
     def keys(self):
-        return self.dict.keys()
+        return list(self.dict.keys())
 
     def values(self):
-        return self.dict.values()
+        return list(self.dict.values())
 
     def delete(self, id):
-        if str(id) in self.dict.keys():
+        if str(id) in list(self.dict.keys()):
             del self.dict[str(id)]
 
-    def iteritems(self):
-        return iter([(i, self.get(i)) for i in xrange(1,Config.MAX_JOBID+1)
+    def items(self):
+        return iter([(i, self.get(i)) for i in range(1,Config.MAX_JOBID+1)
                 if self.get(i) != None])
 
     def _clean(self):
diff --git a/tests/testJobQueue.py b/tests/testJobQueue.py
index 0b6a970c..6bd65266 100644
--- a/tests/testJobQueue.py
+++ b/tests/testJobQueue.py
@@ -1,3 +1,6 @@
+from __future__ import print_function
+from builtins import range
+from builtins import str
 import unittest
 import redis
 
@@ -55,7 +58,7 @@ def test_job(self):
         self.assertTrue(job.isNotAssigned())
 
         self.job1.makeAssigned()
-        print "Checkout:"
+        print("Checkout:")
         self.assertFalse(self.job1.isNotAssigned())
         self.assertFalse(job.isNotAssigned())
 
@@ -127,7 +130,7 @@ def test_makeDead(self):
     def test__getNextID(self):
 
         init_id = self.jobQueue.nextID
-        for i in xrange(1, Config.MAX_JOBID + 100):
+        for i in range(1, Config.MAX_JOBID + 100):
             id = self.jobQueue._getNextID()
             self.assertNotEqual(str(id), self.jobId1)
 
diff --git a/tests/validate.py b/tests/validate.py
index 28b08db5..6f047acb 100644
--- a/tests/validate.py
+++ b/tests/validate.py
@@ -1,3 +1,4 @@
+from __future__ import print_function
 #
 # Recursively validates all python files with pyflakes that were modified
 # since the last validation, and provides basic stats. Ignores hidden
@@ -8,8 +9,8 @@
     import pyflakes
     pyflakes  # avoid unused warning when validating self!
 except ImportError:
-    print 'Validate requires pyflakes. Please install '\
-          'with: pip install pyflakes'
+    print('Validate requires pyflakes. Please install '\
+          'with: pip install pyflakes')
     exit()
 
 import argparse
@@ -46,7 +47,7 @@
 line_count = 0
 
 
-print '\n---- Validating all files ----'
+print('\n---- Validating all files ----')
 
 for dirname, dirnames, filenames in os.walk('.'):
     for filename in filenames:
@@ -77,16 +78,16 @@
             if args.stats:
                 line_count += sum(1 for line in open(path))
 if validated_issue_count == 0:
-    print 'ALL OKAY'
-print '\n---- Validation summary ----'
-print 'Files with validation issues: %i' % validated_issue_count
-print 'Validated files: %i' % validated_count
-print 'Total python files: %i' % file_count
+    print('ALL OKAY')
+print('\n---- Validation summary ----')
+print('Files with validation issues: %i' % validated_issue_count)
+print('Validated files: %i' % validated_count)
+print('Total python files: %i' % file_count)
 
 # Print stats
 if args.stats:
-    print '\n---- Stats ----'
-    print 'Total python line count: %i' % line_count
+    print('\n---- Stats ----')
+    print('Total python line count: %i' % line_count)
 
 # Finish
-print ''
+print('')
diff --git a/vmms/distDocker.py b/vmms/distDocker.py
index 8ea8def2..c773409f 100644
--- a/vmms/distDocker.py
+++ b/vmms/distDocker.py
@@ -8,6 +8,8 @@
 # `domain_name` attribtue of TangoMachine.
 #
 
+from builtins import object
+from builtins import str
 import random, subprocess, re, time, logging, threading, os, sys, shutil
 import tempfile
 import socket
@@ -64,7 +66,7 @@ def timeoutWithReturnStatus(command, time_out, returnValue = 0):
                             stderr=subprocess.STDOUT)
     return ret
 
-class DistDocker:
+class DistDocker(object):
 
     _SSH_FLAGS = ["-q", "-o", "BatchMode=yes" ]
     _SSH_AUTH_FLAGS = [ "-i", os.path.join(os.path.dirname(__file__), "id_rsa"),
@@ -223,7 +225,7 @@ def runJob(self, vm, runTimeout, maxOutputFileSize):
                 self.log.debug("Lost persistent SSH connection")
                 return ret
 
-        autodriverCmd = 'autodriver -u %d -f %d -t %d -o %d autolab &> output/feedback' % \
+        autodriverCmd = 'autodriver -u %d -f %d -t %d -o %d autolab > output/feedback 2>&1' % \
                         (config.Config.VM_ULIMIT_USER_PROC, 
                         config.Config.VM_ULIMIT_FILE_SIZE,
                         runTimeout, config.Config.MAX_OUTPUT_FILE_SIZE)
@@ -335,7 +337,7 @@ def getVMs(self):
             volumes = subprocess.check_output(["ssh"] + DistDocker._SSH_FLAGS +
                                                 DistDocker._SSH_AUTH_FLAGS +
                                                 ["%s@%s" % (self.hostUser, host),
-                                                "(ls %s)" % volumePath]).split('\n')
+                                                "(ls %s)" % volumePath]).decode('utf-8').split('\n')
             for volume in volumes:
                 if re.match("%s-" % config.Config.PREFIX, volume):
                     machine = TangoMachine()
@@ -373,7 +375,7 @@ def getImages(self):
             o = subprocess.check_output(["ssh"] + DistDocker._SSH_FLAGS +
                                         DistDocker._SSH_AUTH_FLAGS +
                                         ["%s@%s" % (self.hostUser, host),
-                                        "(docker images)"])
+                                        "(docker images)"]).decode('utf-8')
             o_l = o.split('\n')
             o_l.pop()
             o_l.reverse()
diff --git a/vmms/ec2SSH.py b/vmms/ec2SSH.py
index 303bf381..4f9eeb0f 100644
--- a/vmms/ec2SSH.py
+++ b/vmms/ec2SSH.py
@@ -8,6 +8,10 @@
 #   Ec2Exception - EC2 raises this if it encounters any problem
 #   ec2CallError - raised by ec2Call() function
 #
+# TODO: this currently probably does not work on Python 3 yet
+
+from builtins import object
+from builtins import str
 import subprocess
 import os
 import re
@@ -81,7 +85,7 @@ class ec2CallError(Exception):
     pass
 
 
-class Ec2SSH:
+class Ec2SSH(object):
     _SSH_FLAGS = ["-i", config.Config.SECURITY_KEY_PATH,
                   "-o", "StrictHostKeyChecking no",
                   "-o", "GSSAPIAuthentication no"]
@@ -341,7 +345,7 @@ def runJob(self, vm, runTimeout, maxOutputFileSize):
                        self.instanceName(vm.id, vm.name))
         # Setting ulimits for VM and running job
         runcmd = "/usr/bin/time --output=time.out autodriver -u %d -f %d -t \
-                %d -o %d autolab &> output" % (config.Config.VM_ULIMIT_USER_PROC,
+                %d -o %d autolab > output 2>&1 " % (config.Config.VM_ULIMIT_USER_PROC,
                                                config.Config.VM_ULIMIT_FILE_SIZE,
                                                runTimeout,
                                                maxOutputFileSize)
@@ -368,7 +372,7 @@ def copyOut(self, vm, destFile):
                     self.ssh_flags +
                     [
                         "%s@%s" % (config.Config.EC2_USER_NAME, domain_name),
-                        'cat time.out']).rstrip('\n')
+                        'cat time.out']).decode('utf-8').rstrip('\n')
 
                 # If the output is empty, then ignore it (timing info wasn't
                 # collected), otherwise let's log it!
diff --git a/vmms/localDocker.py b/vmms/localDocker.py
index 52c030b7..1c89f5c9 100644
--- a/vmms/localDocker.py
+++ b/vmms/localDocker.py
@@ -2,6 +2,8 @@
 # localDocker.py - Implements the Tango VMMS interface to run Tango jobs in 
 #                docker containers. In this context, VMs are docker containers.
 #
+from builtins import object
+from builtins import str
 import random, subprocess, re, time, logging, threading, os, sys, shutil
 import config
 from tangoObjects import TangoMachine
@@ -60,7 +62,7 @@ def timeoutWithReturnStatus(command, time_out, returnValue = 0):
 # User defined exceptions
 #
 
-class LocalDocker:
+class LocalDocker(object):
 
     def __init__(self):
         """ Checks if the machine is ready to run docker containers.
@@ -137,7 +139,7 @@ def runJob(self, vm, runTimeout, maxOutputFileSize):
         args = args + [vm.image]
         args = args + ['sh', '-c']
 
-        autodriverCmd = 'autodriver -u %d -f %d -t %d -o %d autolab &> output/feedback' % \
+        autodriverCmd = 'autodriver -u %d -f %d -t %d -o %d autolab > output/feedback 2>&1' % \
                         (config.Config.VM_ULIMIT_USER_PROC, 
                         config.Config.VM_ULIMIT_FILE_SIZE,
                         runTimeout, config.Config.MAX_OUTPUT_FILE_SIZE)
@@ -227,7 +229,7 @@ def getImages(self):
         """
         result = set()
         cmd = "docker images"
-        o = subprocess.check_output("docker images", shell=True)
+        o = subprocess.check_output("docker images", shell=True).decode('utf-8')
         o_l = o.split('\n')
         o_l.pop()
         o_l.reverse()
diff --git a/vmms/tashiSSH.py b/vmms/tashiSSH.py
index ea05e114..57db80e7 100644
--- a/vmms/tashiSSH.py
+++ b/vmms/tashiSSH.py
@@ -8,6 +8,9 @@
 #   TashiException - Tashi raises this if it encounters any problem
 #   tashiCallError - raised by tashiCall() function
 #
+# TODO: this currently probably does not work on Python 3 yet
+from builtins import object
+from builtins import str
 import random
 import subprocess
 import os
@@ -93,7 +96,7 @@ class tashiCallError(Exception):
     pass
 
 
-class TashiSSH:
+class TashiSSH(object):
     _SSH_FLAGS = ["-q", "-i", os.path.dirname(__file__) + "/id_rsa",
                   "-o", "StrictHostKeyChecking=no",
                   "-o", "GSSAPIAuthentication=no"]
@@ -278,7 +281,7 @@ def runJob(self, vm, runTimeout, maxOutputFileSize):
         self.log.debug("runJob: Running job on VM %s" % domain_name)
         # Setting ulimits for VM and running job
         runcmd = "/usr/bin/time --output=time.out autodriver -u %d -f %d -t \
-            %d -o %d autolab &> output" % (config.Config.VM_ULIMIT_USER_PROC,
+            %d -o %d autolab > output 2>&1 " % (config.Config.VM_ULIMIT_USER_PROC,
                                            config.Config.VM_ULIMIT_FILE_SIZE,
                                            runTimeout,
                                            config.Config.MAX_OUTPUT_FILE_SIZE)
@@ -307,7 +310,7 @@ def copyOut(self, vm, destFile):
                     [
                         'autolab@%s' %
                         (domain_name),
-                        'cat time.out']).rstrip('\n')
+                        'cat time.out']).decode('utf-8').rstrip('\n')
 
                 # If the output is empty, then ignore it (timing info wasn't
                 # collected), otherwise let's log it!
diff --git a/worker.py b/worker.py
index e7ffec25..dc9ca674 100644
--- a/worker.py
+++ b/worker.py
@@ -1,6 +1,7 @@
 #
 # worker.py - Thread that shepherds a job through it execution sequence
 #
+from builtins import str
 import threading
 import time
 import logging
@@ -119,7 +120,7 @@ def catFiles(self, f1, f2):
         """
         self.appendMsg(f1, "Here is the output from the autograder:\n---")
         (wfd, tmpname)=tempfile.mkstemp(dir=os.path.dirname(f2))
-        wf=os.fdopen(wfd, "a")
+        wf=os.fdopen(wfd, "ab")
         with open(f1, "rb") as f1fd:
             shutil.copyfileobj(f1fd, wf)
         # f2 may not exist if autograder failed
@@ -138,7 +139,7 @@ def notifyServer(self, job):
                 outputFileName = job.outputFile.split(
                     "/")[-1]  # get filename from path
                 fh = open(job.outputFile, 'rb')
-                files = {'file': unicode(fh.read(), errors='ignore')}
+                files = {'file': str(fh.read(), errors='ignore')}
                 hdrs = {'Filename': outputFileName}
                 self.log.debug("Sending request to %s" % job.notifyURL)
                 response = requests.post(