diff --git a/src/TruffleSqueak-Tests.package/TruffleSqueakTest.class/instance/testCallTarget.st b/src/TruffleSqueak-Tests.package/TruffleSqueakTest.class/instance/testCallTarget.st
new file mode 100644
index 000000000..678e035bd
--- /dev/null
+++ b/src/TruffleSqueak-Tests.package/TruffleSqueakTest.class/instance/testCallTarget.st
@@ -0,0 +1,11 @@
+testing
+testCallTarget
+	| method string |
+	Java primitiveIsHostLookupAllowed ifFalse: [ ^ false ].
+	
+	method := SmallInteger >> #/.
+
+	self deny: method callTarget isNil.
+
+	string := CallTargetBrowser callTargetInfoStringFor: method.
+	self assert: (string includesSubstring: 'knownCallSiteCount')
\ No newline at end of file
diff --git a/src/TruffleSqueak-Tests.package/TruffleSqueakTest.class/methodProperties.json b/src/TruffleSqueak-Tests.package/TruffleSqueakTest.class/methodProperties.json
index 5a701157f..aff9acf48 100644
--- a/src/TruffleSqueak-Tests.package/TruffleSqueakTest.class/methodProperties.json
+++ b/src/TruffleSqueak-Tests.package/TruffleSqueakTest.class/methodProperties.json
@@ -5,6 +5,7 @@
 		"assertSorted:name:" : "fn 1/25/2020 15:24",
 		"testAdoptInstanceArrays" : "fn 1/31/2020 10:20",
 		"testArrayStatistics" : "fn 5/13/2020 17:37",
+		"testCallTarget" : "fn 2/18/2021 09:20",
 		"testLayoutStatistics" : "fn 5/13/2020 17:37",
 		"testTestMapConsistency" : "fn 12/17/2020 19:52",
 		"testVMIntrospection" : "fn 2/1/2021 15:00" } }
diff --git a/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/README.md b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/README.md
new file mode 100644
index 000000000..e69de29bb
diff --git a/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/class/callTargetInfoStringFor..st b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/class/callTargetInfoStringFor..st
new file mode 100644
index 000000000..98321eaf4
--- /dev/null
+++ b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/class/callTargetInfoStringFor..st
@@ -0,0 +1,27 @@
+helpers
+callTargetInfoStringFor: aCompiledMethod
+	^ aCompiledMethod callTarget
+		ifNil: [ 'no call target available' ]
+		ifNotNil: [ :c |
+'name:					{1}
+callCount:				{2}
+callAndLoopCount:		{3}
+knownCallSiteCount:	{4}
+nonTrivialNodeCount:	{5}
+profiled return value:	{6}
+profiled arguments:		{7}' format: {
+	c getName asString.
+	c getCallCount.
+	c getCallAndLoopCount.
+	c getKnownCallSiteCount.
+	c getNonTrivialNodeCount.
+	c returnProfile
+		ifNil: [ 'unknown' ]
+		ifNotNil: [ :p | p getType ifNil: [ 'unknown' ] ifNotNil: [ :e | e getSimpleName asString ]].
+	c argumentsProfile
+		ifNil: [ 'all unknown' ]
+		ifNotNil: [ :p | p getTypes
+			ifNil: [ 'all unknown' ]
+			ifNotNil: [ :t | ((t asCollection allButFirst: 3) collect: [ :ea | ea
+				ifNil: ['unknown']
+				ifNotNil: [ ea getSimpleName asString ]]) joinSeparatedBy: ', ' ] ] } ]
diff --git a/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/class/showClassIcons.st b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/class/showClassIcons.st
new file mode 100644
index 000000000..0d38e12db
--- /dev/null
+++ b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/class/showClassIcons.st
@@ -0,0 +1,3 @@
+preferences
+showClassIcons
+	^ false
\ No newline at end of file
diff --git a/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/class/showMessageIcons.st b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/class/showMessageIcons.st
new file mode 100644
index 000000000..070aaa7a8
--- /dev/null
+++ b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/class/showMessageIcons.st
@@ -0,0 +1,3 @@
+preferences
+showMessageIcons
+	^ false
\ No newline at end of file
diff --git a/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/callTargetInfoContents.st b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/callTargetInfoContents.st
new file mode 100644
index 000000000..ed3c9f726
--- /dev/null
+++ b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/callTargetInfoContents.st
@@ -0,0 +1,6 @@
+message list
+callTargetInfoContents
+	^ contents := self selectedClassOrMetaClass methodDict
+		at: self selectedMessageName
+		ifPresent: [ :cm | self class callTargetInfoStringFor: cm ]
+		ifAbsent: [ 'not found' ]
diff --git a/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/contentsSymbolQuints.st b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/contentsSymbolQuints.st
new file mode 100644
index 000000000..83c5d9e60
--- /dev/null
+++ b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/contentsSymbolQuints.st
@@ -0,0 +1,4 @@
+controls
+contentsSymbolQuints
+	^ super contentsSymbolQuints, #(#-
+		(callTargetInfo toggleCallTargetInfo showingCallTargetInfoString 'call target' 'information on underlying call target'))
\ No newline at end of file
diff --git a/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/countsToMessages..st b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/countsToMessages..st
new file mode 100644
index 000000000..835eb35a8
--- /dev/null
+++ b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/countsToMessages..st
@@ -0,0 +1,16 @@
+helpers
+countsToMessages: aMessageList
+	| result |
+	result := Dictionary new.
+	aMessageList do: [ :ea | | callTarget |
+		callTarget := (self selectedClassOrMetaClass >> ea asSymbol) callTarget.
+		result
+			at: (callTarget ifNil: [-1] ifNotNil: [ :c |
+				self sortBy caseOf: {
+					[#callCount] -> [ c getCallCount ln ].
+					[#callAndLoopCount] -> [ c getCallAndLoopCount ln ].
+					[#knownCallSiteCount] -> [ c getKnownCallSiteCount ].
+					[#nonTrivialNodeCount] -> [ c getNonTrivialNodeCount ] } ] )
+			ifPresent: [ :v | v add: ea ]
+			ifAbsentPut: [ OrderedCollection with: ea ] ].
+	^ result
\ No newline at end of file
diff --git a/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/defaultBrowserTitle.st b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/defaultBrowserTitle.st
new file mode 100644
index 000000000..e5d7d2655
--- /dev/null
+++ b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/defaultBrowserTitle.st
@@ -0,0 +1,3 @@
+initialize-release
+defaultBrowserTitle
+	^  'CallTarget Browser'
\ No newline at end of file
diff --git a/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/formattedLabel.forSelector.inClass..st b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/formattedLabel.forSelector.inClass..st
new file mode 100644
index 000000000..bd61fc67f
--- /dev/null
+++ b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/formattedLabel.forSelector.inClass..st
@@ -0,0 +1,3 @@
+message list
+formattedLabel: aString forSelector: aSymbol inClass: aClass
+	^ aString
\ No newline at end of file
diff --git a/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/inspectCallTarget.st b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/inspectCallTarget.st
new file mode 100644
index 000000000..1877db596
--- /dev/null
+++ b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/inspectCallTarget.st
@@ -0,0 +1,6 @@
+message functions
+inspectCallTarget
+	(self selectedClassOrMetaClass
+		compiledMethodAt: self selectedMessageName
+		ifAbsent: []) ifNotNil:
+			[:method| method callTarget inspect]
\ No newline at end of file
diff --git a/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/mainMessageListMenu..st b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/mainMessageListMenu..st
new file mode 100644
index 000000000..d74adf039
--- /dev/null
+++ b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/mainMessageListMenu..st
@@ -0,0 +1,12 @@
+message functions
+mainMessageListMenu: aMenu 
+	^ (super mainMessageListMenu: aMenu)
+		add: 'inspect call target' action: #inspectCallTarget;
+		addLine;
+		add: 'sort alphabetically' action: #sortAlphabetically;
+		add: 'sort by call and loop count (default)' action: #sortByCallAndLoopCount;
+		add: 'sort by call count' action: #sortByCallCount;
+		add: 'sort by known call site count' action: #sortByKnownCallSiteCount;
+		add: 'sort by non-trivial node count' action: #sortByNonTrivialNodeCount;
+		addLine;
+		yourself
\ No newline at end of file
diff --git a/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/messageList.st b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/messageList.st
new file mode 100644
index 000000000..0b6f5b353
--- /dev/null
+++ b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/messageList.st
@@ -0,0 +1,16 @@
+message list
+messageList
+	| messages countsToMessages sortedCounts highestCount result |
+	messages := super messageList.
+	(self sortBy == #alphabetically or: [ messages isEmpty])
+		ifTrue: [ ^ messages ].
+	countsToMessages := self countsToMessages: messages.
+	result := OrderedCollection new.
+	sortedCounts := countsToMessages keysInOrder reversed.
+	highestCount := sortedCounts first.
+	sortedCounts do: [ :count |
+		result addAll: ((countsToMessages at: count) collect: [ :ea |
+			ea asText
+				addAttribute: (self textColorFor: count with: highestCount)
+				yourself])].
+	^ result
\ No newline at end of file
diff --git a/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/selectedMessage.st b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/selectedMessage.st
new file mode 100644
index 000000000..c3f2e5b68
--- /dev/null
+++ b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/selectedMessage.st
@@ -0,0 +1,8 @@
+message list
+selectedMessage
+	contents == nil ifFalse: [^ contents copy].
+
+	self showingCallTargetInfo ifTrue:
+		[ ^ self callTargetInfoContents ].
+
+	^ super selectedMessage
\ No newline at end of file
diff --git a/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/showCallTargetInfo..st b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/showCallTargetInfo..st
new file mode 100644
index 000000000..a71848a63
--- /dev/null
+++ b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/showCallTargetInfo..st
@@ -0,0 +1,3 @@
+what to show
+showCallTargetInfo: aBoolean
+	self contentsSymbol: (aBoolean ifFalse: [#source] ifTrue: [#callTargetInfo])
\ No newline at end of file
diff --git a/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/showingCallTargetInfo.st b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/showingCallTargetInfo.st
new file mode 100644
index 000000000..d73d5cc5f
--- /dev/null
+++ b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/showingCallTargetInfo.st
@@ -0,0 +1,3 @@
+what to show
+showingCallTargetInfo
+	^ contentsSymbol == #callTargetInfo
\ No newline at end of file
diff --git a/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/showingCallTargetInfoString.st b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/showingCallTargetInfoString.st
new file mode 100644
index 000000000..25cb07f3b
--- /dev/null
+++ b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/showingCallTargetInfoString.st
@@ -0,0 +1,9 @@
+what to show
+showingCallTargetInfoString
+	"Answer a string telling whether the receiver is showing plain source"
+
+	^ (self showingCallTargetInfo
+		ifTrue:
+			['<yes>']
+		ifFalse:
+			['<no>']), 'call target'
\ No newline at end of file
diff --git a/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/sortAlphabetically.st b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/sortAlphabetically.st
new file mode 100644
index 000000000..7e4c35fe8
--- /dev/null
+++ b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/sortAlphabetically.st
@@ -0,0 +1,3 @@
+actions
+sortAlphabetically
+	self sortBy: #alphabetically
\ No newline at end of file
diff --git a/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/sortBy..st b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/sortBy..st
new file mode 100644
index 000000000..c3bd9197a
--- /dev/null
+++ b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/sortBy..st
@@ -0,0 +1,4 @@
+accessing
+sortBy: anObject
+
+	sortBy := anObject.
\ No newline at end of file
diff --git a/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/sortBy.st b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/sortBy.st
new file mode 100644
index 000000000..bb0bc6203
--- /dev/null
+++ b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/sortBy.st
@@ -0,0 +1,4 @@
+accessing
+sortBy
+
+	^ sortBy ifNil: [ sortBy := #callAndLoopCount ]
\ No newline at end of file
diff --git a/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/sortByCallAndLoopCount.st b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/sortByCallAndLoopCount.st
new file mode 100644
index 000000000..000af1a1b
--- /dev/null
+++ b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/sortByCallAndLoopCount.st
@@ -0,0 +1,3 @@
+actions
+sortByCallAndLoopCount
+	self sortBy: #callAndLoopCount
\ No newline at end of file
diff --git a/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/sortByCallCount.st b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/sortByCallCount.st
new file mode 100644
index 000000000..819917256
--- /dev/null
+++ b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/sortByCallCount.st
@@ -0,0 +1,3 @@
+actions
+sortByCallCount
+	self sortBy: #callCount
\ No newline at end of file
diff --git a/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/sortByKnownCallSiteCount.st b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/sortByKnownCallSiteCount.st
new file mode 100644
index 000000000..6e9a53344
--- /dev/null
+++ b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/sortByKnownCallSiteCount.st
@@ -0,0 +1,3 @@
+actions
+sortByKnownCallSiteCount
+	self sortBy: #knownCallSiteCount
\ No newline at end of file
diff --git a/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/sortByNonTrivialNodeCount.st b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/sortByNonTrivialNodeCount.st
new file mode 100644
index 000000000..398b657e1
--- /dev/null
+++ b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/sortByNonTrivialNodeCount.st
@@ -0,0 +1,3 @@
+actions
+sortByNonTrivialNodeCount
+	self sortBy: #nonTrivialNodeCount
\ No newline at end of file
diff --git a/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/textColorFor.with..st b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/textColorFor.with..st
new file mode 100644
index 000000000..3c59a1327
--- /dev/null
+++ b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/textColorFor.with..st
@@ -0,0 +1,11 @@
+helpers
+textColorFor: aCount with: aMax
+	
+	^ aCount >= 0
+		ifTrue: [ | r |
+			r := 1.0 * aCount / aMax.
+			TextColor color: (Color
+				r: r
+				g: 0
+				b: 1.0 - r) ]
+		ifFalse: [ TextColor gray]
\ No newline at end of file
diff --git a/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/toggleCallTargetInfo.st b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/toggleCallTargetInfo.st
new file mode 100644
index 000000000..e045e9a2a
--- /dev/null
+++ b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/instance/toggleCallTargetInfo.st
@@ -0,0 +1,9 @@
+what to show
+toggleCallTargetInfo
+	| wasShowing |
+	self okToChange ifTrue:
+		[wasShowing := self showingCallTargetInfo.
+		self restoreTextualCodingPane.
+		self showCallTargetInfo: wasShowing not.
+		self setContentsToForceRefetch.
+		self contentsChanged]
\ No newline at end of file
diff --git a/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/methodProperties.json b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/methodProperties.json
new file mode 100644
index 000000000..026cfd164
--- /dev/null
+++ b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/methodProperties.json
@@ -0,0 +1,27 @@
+{
+	"class" : {
+		"callTargetInfoStringFor:" : "fn 2/18/2021 09:14",
+		"showClassIcons" : "fn 2/16/2021 22:17",
+		"showMessageIcons" : "fn 2/16/2021 22:17" },
+	"instance" : {
+		"callTargetInfoContents" : "fn 2/18/2021 10:12",
+		"contentsSymbolQuints" : "fn 2/17/2021 12:00",
+		"countsToMessages:" : "fn 2/17/2021 14:33",
+		"defaultBrowserTitle" : "fn 2/16/2021 16:54",
+		"formattedLabel:forSelector:inClass:" : "fn 2/16/2021 22:10",
+		"inspectCallTarget" : "fn 2/17/2021 14:50",
+		"mainMessageListMenu:" : "fn 2/17/2021 14:51",
+		"messageList" : "fn 2/16/2021 22:13",
+		"selectedMessage" : "fn 2/17/2021 12:26",
+		"showCallTargetInfo:" : "fn 2/17/2021 12:28",
+		"showingCallTargetInfo" : "fn 2/17/2021 12:01",
+		"showingCallTargetInfoString" : "fn 2/17/2021 12:01",
+		"sortAlphabetically" : "fn 2/16/2021 17:44",
+		"sortBy" : "fn 2/16/2021 17:33",
+		"sortBy:" : "fn 2/16/2021 17:27",
+		"sortByCallAndLoopCount" : "fn 2/16/2021 17:33",
+		"sortByCallCount" : "fn 2/16/2021 17:30",
+		"sortByKnownCallSiteCount" : "fn 2/16/2021 17:39",
+		"sortByNonTrivialNodeCount" : "fn 2/16/2021 17:39",
+		"textColorFor:with:" : "fn 2/17/2021 11:08",
+		"toggleCallTargetInfo" : "fn 2/17/2021 12:28" } }
diff --git a/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/properties.json b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/properties.json
new file mode 100644
index 000000000..2199beded
--- /dev/null
+++ b/src/TruffleSqueak-Utilities.package/CallTargetBrowser.class/properties.json
@@ -0,0 +1,14 @@
+{
+	"category" : "TruffleSqueak-Utilities",
+	"classinstvars" : [
+		 ],
+	"classvars" : [
+		 ],
+	"commentStamp" : "",
+	"instvars" : [
+		"sortBy" ],
+	"name" : "CallTargetBrowser",
+	"pools" : [
+		 ],
+	"super" : "Browser",
+	"type" : "normal" }
diff --git a/src/TruffleSqueak-Utilities.package/CompiledMethod.extension/instance/callTarget.st b/src/TruffleSqueak-Utilities.package/CompiledMethod.extension/instance/callTarget.st
new file mode 100644
index 000000000..52bfa0d97
--- /dev/null
+++ b/src/TruffleSqueak-Utilities.package/CompiledMethod.extension/instance/callTarget.st
@@ -0,0 +1,4 @@
+*TruffleSqueak-Utilities
+callTarget
+	<primitive: 'primitiveGetCallTarget' module: 'TruffleSqueakPlugin'>
+	^ nil
\ No newline at end of file
diff --git a/src/TruffleSqueak-Utilities.package/CompiledMethod.extension/methodProperties.json b/src/TruffleSqueak-Utilities.package/CompiledMethod.extension/methodProperties.json
new file mode 100644
index 000000000..a5b49dc0b
--- /dev/null
+++ b/src/TruffleSqueak-Utilities.package/CompiledMethod.extension/methodProperties.json
@@ -0,0 +1,5 @@
+{
+	"class" : {
+		 },
+	"instance" : {
+		"callTarget" : "fn 2/16/2021 17:00" } }
diff --git a/src/TruffleSqueak-Utilities.package/CompiledMethod.extension/properties.json b/src/TruffleSqueak-Utilities.package/CompiledMethod.extension/properties.json
new file mode 100644
index 000000000..c19cf97ea
--- /dev/null
+++ b/src/TruffleSqueak-Utilities.package/CompiledMethod.extension/properties.json
@@ -0,0 +1,2 @@
+{
+	"name" : "CompiledMethod" }