diff --git a/services/web/app/views/project/editor/review-panel.jade b/services/web/app/views/project/editor/review-panel.jade
index 3e82e56daa..7c3779b079 100644
--- a/services/web/app/views/project/editor/review-panel.jade
+++ b/services/web/app/views/project/editor/review-panel.jade
@@ -23,8 +23,10 @@
 					comment-entry(
 						entry="entry"
 						users="users"
-						on-resolve=""
-						on-reply="submitReply(entry);"
+						on-resolve="resolveComment(entry, entry_id)"
+						on-unresolve="unresolveComment(entry_id)"
+						on-delete="deleteComment(entry_id)"
+						on-reply="submitReply(entry, entry_id);"
 						on-indicator-click="toggleReviewPanel();"
 					)
 				
@@ -61,8 +63,10 @@
 					comment-entry(
 						entry="entry"
 						users="users"
-						on-resolve=""
-						on-reply="submitReply(entry);"
+						on-resolve="resolveComment(entry, entry_id)"
+						on-unresolve="unresolveComment(entry_id)"
+						on-delete="deleteComment(entry_id)"
+						on-reply="submitReply(entry, entry_id);"
 						on-indicator-click="toggleReviewPanel();"
 						ng-click="gotoEntry(doc_id, entry)"
 					)
@@ -122,7 +126,7 @@ script(type='text/ng-template', id='changeEntryTemplate')
 
 script(type='text/ng-template', id='commentEntryTemplate')
 	div
-		.rp-entry-callout.rp-entry-callout-comment
+		.rp-entry-callout.rp-entry-callout-comment(ng-if="!entry.resolved")
 		.rp-entry-indicator(
 			ng-class="{ 'rp-entry-indicator-focused': entry.focused }"
 			ng-click="onIndicatorClick();"
@@ -132,6 +136,7 @@ script(type='text/ng-template', id='commentEntryTemplate')
 			ng-class="entry.focused ? 'rp-entry-focused' : '';"
 		)
 			.rp-comment(
+				ng-if="!entry.resolved || entry.showWhenResolved"
 				ng-repeat="comment in entry.thread"
 				ng-class="users[comment.user_id].isSelf ? 'rp-comment-self' : '';"
 			)
@@ -145,16 +150,24 @@ script(type='text/ng-template', id='commentEntryTemplate')
 						| {{ comment.ts | date : 'MMM d, y h:mm a' }}
 						|  • 
 						span(style="color: hsl({{ users[comment.user_id].hue }}, 70%, 40%);") {{ users[comment.user_id].name }}
-			.rp-comment-reply
+			.rp-comment-reply(ng-if="!entry.resolved || entry.showWhenResolved")
 				textarea.rp-comment-input(
 					ng-model="entry.replyContent"
 					ng-keypress="handleCommentReplyKeyPress($event);"
-					placeholder="Hit \"Enter\" to reply"
+					placeholder="{{ 'Hit \"Enter\" to reply' + (entry.resolved ? ' and re-open' : '') }}"
 				)
+			.rp-comment-resolved-description(ng-if="entry.resolved && !entry.showWhenResolved")
+				| Resolved Comment
+				a(href, ng-click="entry.showWhenResolved = true") Show
 			.rp-entry-actions
-				a.rp-entry-button(href, ng-click="onResolve();") 
+				a.rp-entry-button(href, ng-click="onResolve();", ng-if="!entry.resolved") 
 					i.fa.fa-check
 					|  Mark as resolved
+				a.rp-entry-button(href, ng-click="onUnresolve();", ng-if="entry.resolved") 
+					|  Re-open
+				a.rp-entry-button(href, ng-click="onDelete();", ng-if="entry.resolved") 
+					|  Delete
+				
 
 script(type='text/ng-template', id='addCommentEntryTemplate')
 	div
diff --git a/services/web/public/coffee/ide/editor/directives/aceEditor/track-changes/TrackChangesManager.coffee b/services/web/public/coffee/ide/editor/directives/aceEditor/track-changes/TrackChangesManager.coffee
index 9c9a2bd7bc..95a10befcd 100644
--- a/services/web/public/coffee/ide/editor/directives/aceEditor/track-changes/TrackChangesManager.coffee
+++ b/services/web/public/coffee/ide/editor/directives/aceEditor/track-changes/TrackChangesManager.coffee
@@ -44,6 +44,15 @@ define [
 			
 			@$scope.$on "change:reject", (e, change_id) =>
 				@rejectChangeId(change_id)
+			
+			@$scope.$on "comment:remove", (e, comment_id) =>
+				@removeCommentId(comment_id)
+			
+			@$scope.$on "comment:resolve", (e, comment_id) =>
+				@resolveCommentId(comment_id)
+			
+			@$scope.$on "comment:unresolve", (e, comment_id) =>
+				@unresolveCommentId(comment_id)
 
 			onChange = (e) =>
 				if !@editor.initing and @enabled
@@ -92,7 +101,10 @@ define [
 				@changesTracker.off "delete:removed"
 				@changesTracker.off "changes:moved"
 				@changesTracker.off "comment:added"
+				@changesTracker.off "comment:moved"
 				@changesTracker.off "comment:removed"
+				@changesTracker.off "comment:resolved"
+				@changesTracker.off "comment:unresolved"
 		
 		connectToChangesTracker: () ->
 			@changesTracker.track_changes = @$scope.trackNewChanges
@@ -119,6 +131,15 @@ define [
 			@changesTracker.on "comment:moved", (comment) =>
 				sl_console.log "[comment:moved]", comment
 				@_onCommentMoved(comment)
+			@changesTracker.on "comment:removed", (comment) =>
+				sl_console.log "[comment:removed]", comment
+				@_onCommentRemoved(comment)
+			@changesTracker.on "comment:resolved", (comment) =>
+				sl_console.log "[comment:resolved]", comment
+				@_onCommentRemoved(comment)
+			@changesTracker.on "comment:unresolved", (comment) =>
+				sl_console.log "[comment:unresolved]", comment
+				@_onCommentAdded(comment)
 			
 		redrawAnnotations: () ->
 			for change in @changesTracker.changes
@@ -179,6 +200,14 @@ define [
 			else
 				throw new Error("unknown change: #{JSON.stringify(change)}")
 
+		removeCommentId: (comment_id) ->
+			@changesTracker.removeCommentId(comment_id)
+
+		resolveCommentId: (comment_id) ->
+			@changesTracker.resolveCommentId(comment_id)
+			
+		unresolveCommentId: (comment_id) ->
+			@changesTracker.unresolveCommentId(comment_id)
 
 		checkMapping: () ->
 			session = @editor.getSession()
@@ -190,22 +219,24 @@ define [
 
 			expected_markers = []
 			for change in @changesTracker.changes
-				op = change.op
-				{background_marker_id, callout_marker_id} = @changeIdToMarkerIdMap[change.id]
-				start = @_shareJsOffsetToAcePosition(op.p)
-				if op.i?
-					end = @_shareJsOffsetToAcePosition(op.p + op.i.length)
-				else if op.d?
-					end = start
-				expected_markers.push { marker_id: background_marker_id, start, end }
-				expected_markers.push { marker_id: callout_marker_id, start, end: start }
+				if @changeIdToMarkerIdMap[change.id]?
+					op = change.op
+					{background_marker_id, callout_marker_id} = @changeIdToMarkerIdMap[change.id]
+					start = @_shareJsOffsetToAcePosition(op.p)
+					if op.i?
+						end = @_shareJsOffsetToAcePosition(op.p + op.i.length)
+					else if op.d?
+						end = start
+					expected_markers.push { marker_id: background_marker_id, start, end }
+					expected_markers.push { marker_id: callout_marker_id, start, end: start }
 			
 			for comment in @changesTracker.comments
-				{background_marker_id, callout_marker_id} = @changeIdToMarkerIdMap[comment.id]
-				start = @_shareJsOffsetToAcePosition(comment.offset)
-				end = @_shareJsOffsetToAcePosition(comment.offset + comment.length)
-				expected_markers.push { marker_id: background_marker_id, start, end }
-				expected_markers.push { marker_id: callout_marker_id, start, end: start }
+				if @changeIdToMarkerIdMap[comment.id]?
+					{background_marker_id, callout_marker_id} = @changeIdToMarkerIdMap[comment.id]
+					start = @_shareJsOffsetToAcePosition(comment.offset)
+					end = @_shareJsOffsetToAcePosition(comment.offset + comment.length)
+					expected_markers.push { marker_id: background_marker_id, start, end }
+					expected_markers.push { marker_id: callout_marker_id, start, end: start }
 			
 			for {marker_id, start, end} in expected_markers
 				marker = markers[marker_id]
@@ -253,6 +284,7 @@ define [
 				new_entry = {
 					type: "comment"
 					thread: comment.metadata.thread
+					resolved: comment.metadata.resolved
 					offset: comment.offset
 					length: comment.length
 				}
@@ -281,7 +313,7 @@ define [
 				}
 
 			for id, entry of entries
-				if entry.type == "comment"
+				if entry.type == "comment" and not entry.resolved
 					entry.focused = (entry.offset <= cursor_offset <= entry.offset + entry.length)
 				else if entry.type == "insert"
 					entry.focused = (entry.offset <= cursor_offset <= entry.offset + entry.content.length)
@@ -363,6 +395,7 @@ define [
 		
 		_onInsertRemoved: (change) ->
 			{background_marker_id, callout_marker_id} = @changeIdToMarkerIdMap[change.id]
+			delete @changeIdToMarkerIdMap[change.id]
 			session = @editor.getSession()
 			session.removeMarker background_marker_id
 			session.removeMarker callout_marker_id
@@ -370,20 +403,33 @@ define [
 		
 		_onDeleteRemoved: (change) ->
 			{background_marker_id, callout_marker_id} = @changeIdToMarkerIdMap[change.id]
+			delete @changeIdToMarkerIdMap[change.id]
 			session = @editor.getSession()
 			session.removeMarker background_marker_id
 			session.removeMarker callout_marker_id
 			@updateReviewEntriesScope()
 		
 		_onCommentAdded: (comment) ->
-			start = @_shareJsOffsetToAcePosition(comment.offset)
-			end = @_shareJsOffsetToAcePosition(comment.offset + comment.length)
-			session = @editor.getSession()
-			doc = session.getDocument()
-			background_range = new Range(start.row, start.column, end.row, end.column)
-			background_marker_id = session.addMarker background_range, "track-changes-marker track-changes-comment-marker", "text"
-			callout_marker_id = @_createCalloutMarker(start, "track-changes-comment-marker-callout")
-			@changeIdToMarkerIdMap[comment.id] = { background_marker_id, callout_marker_id }
+			if !@changeIdToMarkerIdMap[comment.id]?
+				# Only create new markers if they don't already exist
+				start = @_shareJsOffsetToAcePosition(comment.offset)
+				end = @_shareJsOffsetToAcePosition(comment.offset + comment.length)
+				session = @editor.getSession()
+				doc = session.getDocument()
+				background_range = new Range(start.row, start.column, end.row, end.column)
+				background_marker_id = session.addMarker background_range, "track-changes-marker track-changes-comment-marker", "text"
+				callout_marker_id = @_createCalloutMarker(start, "track-changes-comment-marker-callout")
+				@changeIdToMarkerIdMap[comment.id] = { background_marker_id, callout_marker_id }
+			@updateReviewEntriesScope()
+		
+		_onCommentRemoved: (comment) ->
+			if @changeIdToMarkerIdMap[comment.id]?
+				# Resolved comments may not have marker ids
+				{background_marker_id, callout_marker_id} = @changeIdToMarkerIdMap[comment.id]
+				delete @changeIdToMarkerIdMap[comment.id]
+				session = @editor.getSession()
+				session.removeMarker background_marker_id
+				session.removeMarker callout_marker_id
 			@updateReviewEntriesScope()
 
 		_aceRangeToShareJs: (range) ->
@@ -436,13 +482,16 @@ define [
 			@updateReviewEntriesScope()
 	
 		_updateMarker: (change_id, start, end) ->
+			return if !@changeIdToMarkerIdMap[change_id]?
 			session = @editor.getSession()
 			markers = session.getMarkers()
 			{background_marker_id, callout_marker_id} = @changeIdToMarkerIdMap[change_id]
-			background_marker = markers[background_marker_id]
-			background_marker.range.start = start
-			background_marker.range.end = end
-			callout_marker = markers[callout_marker_id]
-			callout_marker.range.start = start
-			callout_marker.range.end = start
+			if background_marker_id?
+				background_marker = markers[background_marker_id]
+				background_marker.range.start = start
+				background_marker.range.end = end
+			if callout_marker_id?
+				callout_marker = markers[callout_marker_id]
+				callout_marker.range.start = start
+				callout_marker.range.end = start
 
diff --git a/services/web/public/coffee/ide/review-panel/ChangesTracker.coffee b/services/web/public/coffee/ide/review-panel/ChangesTracker.coffee
index 250f1c6fe1..1ea9852ab1 100644
--- a/services/web/public/coffee/ide/review-panel/ChangesTracker.coffee
+++ b/services/web/public/coffee/ide/review-panel/ChangesTracker.coffee
@@ -61,6 +61,32 @@ define [
 			@emit "comment:added", comment
 			return comment
 		
+		getComment: (comment_id) ->
+			comment = null
+			for c in @comments
+				if c.id == comment_id
+					comment = c
+					break
+			return comment
+		
+		resolveCommentId: (comment_id) ->
+			comment = @getComment(comment_id)
+			return if !comment?
+			comment.metadata.resolved = true
+			@emit "comment:resolved", comment
+		
+		unresolveCommentId: (comment_id) ->
+			comment = @getComment(comment_id)
+			return if !comment?
+			comment.metadata.resolved = false
+			@emit "comment:unresolved", comment
+		
+		removeCommentId: (comment_id) ->
+			comment = @getComment(comment_id)
+			return if !comment?
+			@comments = @comments.filter (c) -> c.id != comment_id
+			@emit "comment:removed", comment
+		
 		getChange: (change_id) ->
 			change = null
 			for c in @changes
diff --git a/services/web/public/coffee/ide/review-panel/controllers/ReviewPanelController.coffee b/services/web/public/coffee/ide/review-panel/controllers/ReviewPanelController.coffee
index e126984cf4..d6027d745c 100644
--- a/services/web/public/coffee/ide/review-panel/controllers/ReviewPanelController.coffee
+++ b/services/web/public/coffee/ide/review-panel/controllers/ReviewPanelController.coffee
@@ -110,7 +110,8 @@ define [
 		# 		ev.target.blur()
 		# 		$scope.submitReply(entry)
 
-		$scope.submitReply = (entry) ->
+		$scope.submitReply = (entry, entry_id) ->
+			$scope.unresolveComment(entry_id)
 			entry.thread.push {
 				content: entry.replyContent
 				ts: new Date()
@@ -141,7 +142,17 @@ define [
 			entry.replying = false
 			entry.replyContent = ""
 			$scope.$broadcast "review-panel:layout"
+
+		$scope.resolveComment = (entry, entry_id) ->
+			entry.showWhenResolved = false
+			$scope.$broadcast "comment:resolve", entry_id
 		
+		$scope.unresolveComment = (entry_id) ->
+			$scope.$broadcast "comment:unresolve", entry_id
+		
+		$scope.deleteComment = (entry_id) ->
+			$scope.$broadcast "comment:remove", entry_id
+
 		$scope.setSubView = (subView) -> 
 			$scope.reviewPanel.subView = subView
 		
diff --git a/services/web/public/coffee/ide/review-panel/directives/commentEntry.coffee b/services/web/public/coffee/ide/review-panel/directives/commentEntry.coffee
index 3fe0bd93cf..1f15f688dd 100644
--- a/services/web/public/coffee/ide/review-panel/directives/commentEntry.coffee
+++ b/services/web/public/coffee/ide/review-panel/directives/commentEntry.coffee
@@ -10,6 +10,8 @@ define [
 			onResolve: "&"
 			onReply: "&"
 			onIndicatorClick: "&"
+			onDelete: "&"
+			onUnresolve: "&"
 		link: (scope, element, attrs) ->
 			scope.handleCommentReplyKeyPress = (ev) ->
 				if ev.keyCode == 13 and !ev.shiftKey and !ev.ctrlKey and !ev.metaKey