diff --git a/sacredboard/app/data/datastorage.py b/sacredboard/app/data/datastorage.py
index bb3f1d5..4a0aae5 100644
--- a/sacredboard/app/data/datastorage.py
+++ b/sacredboard/app/data/datastorage.py
@@ -1,9 +1,11 @@
-"""Interfaces for data storage backend."""
+"""Interfaces for data storage."""
+
 
 class Cursor:
     """Interface that abstracts the cursor object returned from databases."""
 
     def __init__(self):
+        """Declare a new cursor to iterate over runs."""
         pass
 
     def count(self):
@@ -11,16 +13,20 @@ def count(self):
         raise NotImplemented()
 
     def __iter__(self):
+        """Iterate over elements."""
         raise NotImplemented()
 
 
 class DataStorage:
     """
-    Interface for data backends. Defines the API for various data stores --- databases, file stores, etc. --- that
-    sacred supports.
+    Interface for data backends.
+
+    Defines the API for various data stores
+    databases, file stores, etc. --- that sacred supports.
     """
 
     def __init__(self):
+        """Initialize data accessor."""
         pass
 
     def get_run(self, run_id):
diff --git a/sacredboard/app/data/filestorage.py b/sacredboard/app/data/filestorage.py
index 8779da3..2c1daae 100644
--- a/sacredboard/app/data/filestorage.py
+++ b/sacredboard/app/data/filestorage.py
@@ -49,18 +49,20 @@ class FileStoreCursor(Cursor):
     """Implements the cursor for file stores."""
 
     def __init__(self, count, iterable):
+        """Initialize FileStoreCursor with a given iterable."""
         self.iterable = iterable
         self._count = count
 
     def count(self):
         """
         Return the number of runs in this query.
-        
+
         :return: int
         """
         return self._count
 
     def __iter__(self):
+        """Iterate over runs."""
         return iter(self.iterable)
 
 
@@ -68,14 +70,15 @@ class FileStorage(DataStorage):
     """Object to interface with one of sacred's file stores."""
 
     def __init__(self, path_to_dir):
+        """Initialize file storage run accessor."""
         super().__init__()
         self.path_to_dir = os.path.expanduser(path_to_dir)
 
     def get_run(self, run_id):
         """
         Return the run associated with a particular `run_id`.
-        
-        :param run_id: 
+
+        :param run_id:
         :return: dict
         :raises FileNotFoundError
         """
@@ -87,8 +90,10 @@ def get_run(self, run_id):
     def get_runs(self, sort_by=None, sort_direction=None,
                  start=0, limit=None, query={"type": "and", "filters": []}):
         """
-        Return all runs in the file store. If a run is corrupt -- e.g. missing files --- it is skipped.
-        
+        Return all runs in the file store.
+
+        If a run is corrupt, e.g. missing files, it is skipped.
+
         :param sort_by: NotImplemented
         :param sort_direction:  NotImplemented
         :param start: NotImplemented
@@ -106,7 +111,9 @@ def run_iterator():
                 try:
                     yield self.get_run(id)
                 except FileNotFoundError:
-                    # An incomplete experiment is a corrupt experiment. Skip it for now.
+                    # An incomplete experiment is a corrupt experiment.
+                    # Skip it for now.
+                    # TODO
                     pass
 
         count = len(all_run_ids)
diff --git a/sacredboard/app/data/mongodb.py b/sacredboard/app/data/mongodb.py
index 6242e9b..d12a1ee 100755
--- a/sacredboard/app/data/mongodb.py
+++ b/sacredboard/app/data/mongodb.py
@@ -10,13 +10,15 @@ class MongoDbCursor(Cursor):
     """Implements Cursor for mongodb."""
 
     def __init__(self, mongodb_cursor):
+        """Initialize a MongoDB cursor."""
         self.mongodb_cursor = mongodb_cursor
 
     def count(self):
-        """Returns the number of items in this cursor."""
+        """Return the number of items in this cursor."""
         return self.mongodb_cursor.count()
 
     def __iter__(self):
+        """Iterate over runs."""
         return self.mongodb_cursor
 
 
diff --git a/sacredboard/app/process/__init__.py b/sacredboard/app/process/__init__.py
index e69de29..5c22027 100644
--- a/sacredboard/app/process/__init__.py
+++ b/sacredboard/app/process/__init__.py
@@ -0,0 +1 @@
+"""Sacredboard module for launching external processes."""
diff --git a/sacredboard/app/process/process.py b/sacredboard/app/process/process.py
index 0ea9ebd..c34a867 100644
--- a/sacredboard/app/process/process.py
+++ b/sacredboard/app/process/process.py
@@ -1,4 +1,5 @@
 # coding=utf-8
+"""Module for launching processes and reading their output."""
 import atexit
 import os
 import select
@@ -7,9 +8,18 @@
 
 
 class Process:
+    """A process that can be run and read output from."""
+
     instances = []  # type: List[Process]
+    """Instances of all processes."""
 
     def __init__(self, command):
+        """
+        Define a new process but do not start it.
+
+        :param command: A command to start. Parameters separated with spaces
+         or as a list, e.g. "command arg1 arg2" or ["command", "arg1", "arg2"].
+        """
         if type(command == list):
             self.command = command
         else:
@@ -18,6 +28,7 @@ def __init__(self, command):
         self.proc = None  # type: Popen
 
     def run(self):
+        """Run the process."""
         environment = os.environ.copy()
         # necessary for reading from processes that don't flush
         # stdout automatically
@@ -26,9 +37,15 @@ def run(self):
         Process.instances.append(self)
 
     def is_running(self):
+        """Test if the process is running."""
         return self.proc is not None and not bool(self.proc.poll())
 
     def read_line(self, time_limit=None):
+        """
+        Read a line from the process.
+
+        Block or wait for time_limit secs. Timeout does not work on Windows.
+        """
         if self.proc is not None:
             poll_obj = select.poll()
             poll_obj.register(self.proc.stdout, select.POLLIN)
@@ -45,6 +62,7 @@ def read_line(self, time_limit=None):
             return None
 
     def terminate(self, wait=False):
+        """Terminate the process."""
         if self.proc is not None:
             self.proc.stdout.close()
             self.proc.terminate()
@@ -52,6 +70,7 @@ def terminate(self, wait=False):
                 self.proc.wait()
 
     def pid(self):
+        """Get the process id. Returns none for non-running processes."""
         if self.proc is not None:
             return self.proc.pid
         else:
@@ -60,6 +79,7 @@ def pid(self):
     @staticmethod
     def terminate_all(wait=False):
         """
+        Terminate all processes.
 
         :param wait: Wait for each to terminate
         :type wait: bool
@@ -72,6 +92,12 @@ def terminate_all(wait=False):
 
     @staticmethod
     def create_process(command):
+        """
+        Create a process using this factory method. This does not start it.
+
+        :param command: A command to start. Parameters separated with spaces
+         or as a list, e.g. "command arg1 arg2" or ["command", "arg1", "arg2"].
+        """
         if getattr(select, "poll", None) is not None:
             return Process(command)
         else:
@@ -79,12 +105,23 @@ def create_process(command):
 
 
 class WindowsProcess(Process):
+    """A class for a Windows process."""
+
     def __init__(self, command):
+        """
+       Define a new process but do not start it.
+
+       :param command: A command to start. Parameters separated with spaces
+        or as a list, e.g. "command arg1 arg2" or ["command", "arg1", "arg2"].
+       """
         Process.__init__(self, command)
 
     def read_line(self, time_limit=None):
-        """ Time limit has no effect.
-         The operation will always block on Windows."""
+        """
+        Read a line from the process.
+
+        On Windows, this the time_limit has no effect, it always blocks.
+        """
         if self.proc is not None:
             return self.proc.stdout.readline().decode()
         else:
@@ -96,10 +133,15 @@ def read_line(self, time_limit=None):
 
 
 class ProcessError(Exception):
+    """A process-related exception."""
+
     pass
 
 
 class UnexpectedOutputError(ProcessError):
+    """An unexpected output produced by the process."""
+
     def __init__(self, output, expected=None):
+        """Create an unexpected output exception."""
         self.expected = expected
         self.output = output
diff --git a/sacredboard/app/process/tensorboard.py b/sacredboard/app/process/tensorboard.py
index 477e535..570530c 100644
--- a/sacredboard/app/process/tensorboard.py
+++ b/sacredboard/app/process/tensorboard.py
@@ -1,3 +1,4 @@
+"""Module for managing TensorBoard processes."""
 import re
 
 from sacredboard.app.process.process \
@@ -7,6 +8,7 @@
 
 
 def stop_all_tensorboards():
+    """Terminate all TensorBoard instances."""
     for process in Process.instances:
         print("Process '%s', running %d" % (process.command[0],
                                             process.is_running()))
@@ -15,10 +17,22 @@ def stop_all_tensorboards():
 
 
 class TensorboardNotFoundError(ProcessError):
+    """TensorBoard binary not found."""
+
     pass
 
 
 def run_tensorboard(logdir, listen_on="0.0.0.0", tensorboard_args=None):
+    """
+    Launch a new TensorBoard instance.
+
+    :param logdir: Path to a TensorFlow summary directory
+    :param listen_on: The IP address TensorBoard should listen on.
+    :param tensorboard_args: Additional TensorBoard arguments.
+    :return: Returns the port TensorBoard is listening on.
+    :raise UnexpectedOutputError
+    :raise TensorboardNotFoundError
+    """
     if tensorboard_args is None:
         tensorboard_args = []
     tensorboard_instance = Process.create_process(
diff --git a/sacredboard/app/webapi/__init__.py b/sacredboard/app/webapi/__init__.py
index e69de29..dce0b49 100644
--- a/sacredboard/app/webapi/__init__.py
+++ b/sacredboard/app/webapi/__init__.py
@@ -0,0 +1 @@
+"""Defines ways of accessing Runs via HTTP interface."""
diff --git a/sacredboard/app/webapi/routes.py b/sacredboard/app/webapi/routes.py
index f204408..e3c01a6 100644
--- a/sacredboard/app/webapi/routes.py
+++ b/sacredboard/app/webapi/routes.py
@@ -1,4 +1,5 @@
 # coding=utf-8
+"""Define HTTP endpoints for the Sacredboard Web API."""
 import re
 from pathlib import Path
 
@@ -17,27 +18,32 @@
 
 @routes.route("/")
 def index():
+    """Redirect user to the main page."""
     return redirect(url_for("routes.show_runs"))
 
 
 @routes.route("/_tests")
 def tests():
+    """Redirect user to a page with JavaScript tests."""
     return redirect(url_for("static", filename="scripts/tests/index.html"))
 
 
 @routes.route("/runs")
 def show_runs():
+    """Render the main page with a list of experiment runs."""
     # return render_template("runs.html", runs=data.runs(), type=type)
     return render_template("runs.html", runs=[], type=type)
 
 
 @routes.route("/api/run")
 def api_runs():
+    """Return a list of runs as a JSON object."""
     return get_runs()
 
 
 @routes.route("/api/run/<run_id>")
 def api_run(run_id):
+    """Return a single run as a JSON object."""
     data = current_app.config["data"]
     run = data.get_run(run_id)
     records_total = 1 if run is not None else 0
@@ -59,6 +65,7 @@ def api_run(run_id):
 
 @routes.route("/tensorboard/start/<run_id>/<int:tflog_id>")
 def run_tensorboard(run_id, tflog_id):
+    """Launch TensorBoard for a given run ID and log ID of that run."""
     data = current_app.config["data"]
     # optimisticaly suppose the run exists...
     run = data.get_run(run_id)
@@ -79,27 +86,32 @@ def run_tensorboard(run_id, tflog_id):
 
 @routes.route("/tensorboard/stop", methods=['GET', 'POST'])
 def close_tensorboards():
+    """Stop all TensorBoard instances launched by Sacredboard."""
     stop_all_tensorboards()
     return "Stopping tensorboard"
 
 
 @routes.errorhandler(TensorboardNotFoundError)
 def handle_tensorboard_not_found(e):
+    """Handle exception: tensorboard script not found."""
     return "Tensorboard not found on your system." \
            " Please install tensorflow first. Sorry.", 503
 
 
 @routes.errorhandler(TimeoutError)
 def handle_tensorboard_timeout(e):
+    """Handle exception: TensorBoard does not respond."""
     return "Tensorboard does not respond. Sorry.", 503
 
 
 @routes.errorhandler(process.UnexpectedOutputError)
 def handle_tensorboard_unexpected_output(e: process.UnexpectedOutputError):
+    """Handle Exception: TensorBoard has produced an unexpected output."""
     return "Tensorboard outputted '%s'," \
            " but the information expected was: '%s'. Sorry." \
            % (e.output, e.expected), 503
 
 
 def setup_routes(app):
+    """Register all HTTP endpoints defined in this file."""
     app.register_blueprint(routes)
diff --git a/sacredboard/app/webapi/runs.py b/sacredboard/app/webapi/runs.py
index daa7686..10e9669 100644
--- a/sacredboard/app/webapi/runs.py
+++ b/sacredboard/app/webapi/runs.py
@@ -1,15 +1,18 @@
 # coding=utf-8
+"""WebAPI module for handling run-related requests."""
 import json
 
 from flask import current_app, request, Response, render_template
 
 
 def parse_int_arg(name, default):
+    """Return a given URL parameter as int or return the default value."""
     return default if request.args.get(name) is None \
         else int(request.args.get(name))
 
 
 def parse_query_filter():
+    """Parse the Run query filter from the URL as a dictionary."""
     query_string = request.args.get("queryFilter")
     if query_string is None:
         return {"type": "and", "filters": []}
@@ -20,6 +23,7 @@ def parse_query_filter():
 
 
 def get_runs():
+    """Get all runs, sort it and return a response."""
     data = current_app.config["data"]
     draw = parse_int_arg("draw", 1)
     start = parse_int_arg("start", 0)
diff --git a/sacredboard/bootstrap.py b/sacredboard/bootstrap.py
index b68548d..4328d3c 100755
--- a/sacredboard/bootstrap.py
+++ b/sacredboard/bootstrap.py
@@ -37,7 +37,8 @@
                    "or Sacred v0.6 (which used default.runs). "
                    "Default: runs")
 @click.option("-F", default="",
-              help="Path to directory containing experiments.")
+              help="Path to directory containing experiment results of the"
+                   "File Storage observer.")
 @click.option("--no-browser", is_flag=True, default=False,
               help="Do not open web browser automatically.")
 @click.option("--debug", is_flag=True, default=False,