diff --git a/calendar/libxpical/oeDateTimeImpl.cpp b/calendar/libxpical/oeDateTimeImpl.cpp
index f6bf195d45bb..8219699e1645 100644
--- a/calendar/libxpical/oeDateTimeImpl.cpp
+++ b/calendar/libxpical/oeDateTimeImpl.cpp
@@ -35,6 +35,10 @@
  * 
 */
 
+/* This file implements a date-time XPCOM object used to pass date-time values between the frontend and the
+backend. It provides access to individual date-time fields from javascript and translates that data to a 
+icaltimetype structure for the backend.*/
+
 #ifndef WIN32
 #include <unistd.h>
 #endif
diff --git a/calendar/libxpical/oeDateTimeImpl.h b/calendar/libxpical/oeDateTimeImpl.h
index dfa531b3e9fe..6f88c3d18bff 100644
--- a/calendar/libxpical/oeDateTimeImpl.h
+++ b/calendar/libxpical/oeDateTimeImpl.h
@@ -35,6 +35,8 @@
  * 
 */
 
+/* Header file for oeDateTimeImpl.cpp containing its CID and CONTRACTID.*/
+
 #ifndef __OE_DATETIMEIMPL_H__
 #define __OE_DATETIMEIMPL_H__
 
diff --git a/calendar/libxpical/oeICalContainerImpl.cpp b/calendar/libxpical/oeICalContainerImpl.cpp
index 10fb45c7e039..aede51885b7f 100644
--- a/calendar/libxpical/oeICalContainerImpl.cpp
+++ b/calendar/libxpical/oeICalContainerImpl.cpp
@@ -34,6 +34,11 @@
  *
  * ***** END LICENSE BLOCK ***** */
 
+/* This file implements the Container object for calendars. The container is the topmost object in 
+the backend and contains and interact with all calendar objects. It acts as a distributor of global
+commands to individual calendars and a collector of calculated data for global queries.
+*/
+
 #include "oeICalContainerImpl.h"
 #include "nsISupportsArray.h"
 #include "nsComponentManagerUtils.h"
diff --git a/calendar/libxpical/oeICalContainerImpl.h b/calendar/libxpical/oeICalContainerImpl.h
index 5ee75dda5506..6dafbc50f5db 100644
--- a/calendar/libxpical/oeICalContainerImpl.h
+++ b/calendar/libxpical/oeICalContainerImpl.h
@@ -34,6 +34,8 @@
  *
  * ***** END LICENSE BLOCK ***** */
 
+/* Header file for oeICalContainerImpl.cpp containing its CID and CONTRACTID.*/
+
 #include "oeIICal.h"
 #include "oeICalImpl.h"
 #include "oeICalEventImpl.h"
diff --git a/calendar/libxpical/oeICalEventImpl.cpp b/calendar/libxpical/oeICalEventImpl.cpp
index f6afd6d4e8d2..b167c14a6d78 100644
--- a/calendar/libxpical/oeICalEventImpl.cpp
+++ b/calendar/libxpical/oeICalEventImpl.cpp
@@ -36,6 +36,11 @@
  *
  * ***** END LICENSE BLOCK ***** */
 
+/* This file implements an XPCOM object which represents a calendar event. It provides access to individual 
+fields of an event and performs calculations concerning its behaviour. The code for the eventDisplay object
+which is an event with display information added to it is included here as well.
+*/
+
 #include <stdlib.h> // for atol
 
 #include "oeICalEventImpl.h"
diff --git a/calendar/libxpical/oeICalEventImpl.h b/calendar/libxpical/oeICalEventImpl.h
index 3a0561377fdb..e0688f94d246 100644
--- a/calendar/libxpical/oeICalEventImpl.h
+++ b/calendar/libxpical/oeICalEventImpl.h
@@ -34,6 +34,9 @@
  * the terms of any one of the MPL, the GPL or the LGPL.
  *
  * ***** END LICENSE BLOCK ***** */
+ 
+ /* Header file for oeICalEventImpl.cpp containing its CID and CONTRACTID.*/
+
 #ifndef _OEICALEVENTIMPL_H_
 #define _OEICALEVENTIMPL_H_
 
diff --git a/calendar/libxpical/oeICalFactory.cpp b/calendar/libxpical/oeICalFactory.cpp
index 3d593588a900..c8e272786062 100644
--- a/calendar/libxpical/oeICalFactory.cpp
+++ b/calendar/libxpical/oeICalFactory.cpp
@@ -34,6 +34,8 @@
  *
  * ***** END LICENSE BLOCK ***** */
 
+/* Factory implementation of various calendar objects */
+
 #include "oeICalImpl.h"
 #include "oeICalContainerImpl.h"
 #include "oeICalEventImpl.h"
diff --git a/calendar/libxpical/oeICalImpl.cpp b/calendar/libxpical/oeICalImpl.cpp
index c6383577620c..e029f36242d8 100644
--- a/calendar/libxpical/oeICalImpl.cpp
+++ b/calendar/libxpical/oeICalImpl.cpp
@@ -33,6 +33,10 @@
  * the terms of any one of the MPL, the GPL or the LGPL.
  *
  * ***** END LICENSE BLOCK ***** */
+ 
+ /* This file implements an XPCOM object which represents a calendar object. It is a container
+ of events and prepares responses for queries made upon the calendar in whole. The task of reading from
+ and writing to the calendar data storage is currently performed by this object */
 
 #ifndef WIN32
 #include <unistd.h>
diff --git a/calendar/libxpical/oeICalImpl.h b/calendar/libxpical/oeICalImpl.h
index 562ead64eb9b..367e281158c8 100644
--- a/calendar/libxpical/oeICalImpl.h
+++ b/calendar/libxpical/oeICalImpl.h
@@ -33,6 +33,10 @@
  * the terms of any one of the MPL, the GPL or the LGPL.
  *
  * ***** END LICENSE BLOCK ***** */
+ 
+ /* Header file for oeICalImpl.cpp containing its CID and CONTRACTID. It also includes
+ the implementation for an event linked-list used throughout the code */
+ 
 #ifndef _OEICALIMPL_H_
 #define _OEICALIMPL_H_
 
diff --git a/calendar/libxpical/oeICalStartupHandler.cpp b/calendar/libxpical/oeICalStartupHandler.cpp
index 6d7311b32f38..4fa9c9c88dfc 100644
--- a/calendar/libxpical/oeICalStartupHandler.cpp
+++ b/calendar/libxpical/oeICalStartupHandler.cpp
@@ -35,6 +35,9 @@
  *
  * ***** END LICENSE BLOCK ***** */
 
+/* Derived from nsICmdLineHandler this file provides the "-calendar" option 
+for launching calendar */
+
 #include "plstr.h"
 #include "nsString.h"
 #include "oeICalStartupHandler.h"
diff --git a/calendar/libxpical/oeICalStartupHandler.h b/calendar/libxpical/oeICalStartupHandler.h
index 05c0655aacae..cca69ca99f9d 100644
--- a/calendar/libxpical/oeICalStartupHandler.h
+++ b/calendar/libxpical/oeICalStartupHandler.h
@@ -35,6 +35,8 @@
  *
  * ***** END LICENSE BLOCK ***** */
 
+/* Header file for oeICalStartupHandler.cpp containing its CID and CONTRACTID.*/
+
 #ifndef __oeICalStartupHandler_h_
 #define __oeICalStartupHandler_h_
 
diff --git a/calendar/libxpical/oeICalTodoImpl.cpp b/calendar/libxpical/oeICalTodoImpl.cpp
index f3e7bd615837..3fa94ed336cc 100644
--- a/calendar/libxpical/oeICalTodoImpl.cpp
+++ b/calendar/libxpical/oeICalTodoImpl.cpp
@@ -35,6 +35,10 @@
  *
  * ***** END LICENSE BLOCK ***** */
 
+/* This file implements an XPCOM object which represents a calendar task(todo) object. It is a derivation
+of the event object which adds fields exclusive to tasks.
+*/
+
 #ifndef WIN32
 #include <unistd.h>
 #endif
diff --git a/calendar/libxpical/oeICalTodoImpl.h b/calendar/libxpical/oeICalTodoImpl.h
index 7658b0cec060..465571245d16 100644
--- a/calendar/libxpical/oeICalTodoImpl.h
+++ b/calendar/libxpical/oeICalTodoImpl.h
@@ -34,6 +34,9 @@
  * the terms of any one of the MPL, the GPL or the LGPL.
  *
  * ***** END LICENSE BLOCK ***** */
+ 
+ /* Header file for oeICalTodoImpl.cpp containing its CID and CONTRACTID.*/
+
 #ifndef _OEICALTODOIMPL_H_
 #define _OEICALTODOIMPL_H_
 
diff --git a/calendar/libxpical/oeIICal.idl b/calendar/libxpical/oeIICal.idl
index 767093df9b5f..44eb7f59ba4b 100644
--- a/calendar/libxpical/oeIICal.idl
+++ b/calendar/libxpical/oeIICal.idl
@@ -36,6 +36,8 @@
  *
  * ***** END LICENSE BLOCK ***** */
 
+/* The Interface Description of all calendar objects listing various fields and methods of each */
+
 #include "nsISupports.idl"
 #include "nsISupportsArray.idl"
 
diff --git a/calendar/libxpical/token.c b/calendar/libxpical/token.c
index fda11590afa7..5b9a07adc0fb 100644
--- a/calendar/libxpical/token.c
+++ b/calendar/libxpical/token.c
@@ -38,6 +38,8 @@
 ** this software for any purpose.
 */
 
+/*This file was stolen from webtools/mozbot/uuidgen/token.c */
+
 #include <string.h>
 #include <stdio.h>
 #include <stdlib.h>
diff --git a/calendar/libxpical/token.h b/calendar/libxpical/token.h
index 23884312458f..07bdc07d9cfc 100644
--- a/calendar/libxpical/token.h
+++ b/calendar/libxpical/token.h
@@ -38,6 +38,8 @@
 ** this software for any purpose.
 */
 
+/*This file was stolen from webtools/mozbot/uuidgen/token.h */
+
 #ifndef _TOKEN_H_
 #define _TOKEN_H_