diff --git a/CHANGELOG b/CHANGELOG
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,11 @@
+0.5, released 2019-10-11
+
+* Add some more metainformation to the header (sample mode and sample interval)
+* Fix empty sample at start of eventlog
+* Support for biographical and retaining profiling modes if using
+at least GHC-8.10.
+* Fix cost centre profiles to match the output of hp2pretty
+
 0.4, released 2019-09-18
 
 *  BREAKING CHANGE: eventlog2html no longer includes traces which have been generated by "traceEvent" or "traceEventIO" from "Debug.Trace" by default.
diff --git a/eventlog2html.cabal b/eventlog2html.cabal
--- a/eventlog2html.cabal
+++ b/eventlog2html.cabal
@@ -1,5 +1,5 @@
 Name:                eventlog2html
-Version:             0.4.0
+Version:             0.5.0
 Synopsis:            Visualise an eventlog
 Description:         eventlog2html is a library for visualising eventlogs.
                      At the moment, the intended use is to visualise eventlogs
@@ -41,10 +41,10 @@
     base                 >= 4 && < 5,
     blaze-html           >= 0.9.1 && < 0.10,
     bytestring           >= 0.10.8 && < 0.11,
-    containers           >= 0.6.0 && < 0.7,
+    containers           >= 0.5.0 && < 0.7,
     file-embed           >= 0.0.11 && < 0.1,
     filepath             >= 1.4.2 && < 1.5,
-    ghc-events           >= 0.8.0 && < 0.10,
+    ghc-events           >= 0.10.0 && < 0.11,
     hashtables           >= 1.2.3 && < 1.3,
     hvega                >= 0.4.0 && < 0.5,
     mtl                  >= 2.2.2 && < 2.3,
@@ -52,7 +52,8 @@
     semigroups           >= 0.18 && < 0.20,
     text                 >= 1.2.3 && < 1.3,
     time                 >= 1.8.0 && < 2.0,
-    vector               >= 0.11
+    vector               >= 0.11,
+    trie-simple          >= 0.4
 
   GHC-options:         -Wall
   default-language:    Haskell2010
@@ -71,6 +72,7 @@
                        Eventlog.VegaTemplate
 
 Executable eventlog2html
+  GHC-options:         -Wall
   default-language:    Haskell2010
   HS-source-dirs:      main
   Main-is:             Main.hs
diff --git a/main/Main.hs b/main/Main.hs
--- a/main/Main.hs
+++ b/main/Main.hs
@@ -3,17 +3,14 @@
 module Main (main) where
 
 import Control.Monad
-import Data.Aeson (encodeFile, Value, toJSON)
+import Data.Aeson (encodeFile)
 import System.FilePath
 import System.Exit
 import System.IO
 
 import Eventlog.Args (args, Args(..))
-import Eventlog.Bands (bands)
 import Eventlog.HtmlTemplate
 import Eventlog.Data
-import Eventlog.Vega
-import Eventlog.VegaTemplate
 import Eventlog.Types
 
 main :: IO ()
@@ -23,9 +20,9 @@
   argsToOutput a
 
 argsToOutput :: Args -> IO ()
-argsToOutput a@Args{files = files, outputFile = Nothing} =
-  if | json a    -> forM_ files $ \file -> doOneJson a file (file <.> "json")
-     | otherwise -> forM_ files $ \file -> doOneHtml a file (file <.> "html")
+argsToOutput a@Args{files = files', outputFile = Nothing} =
+  if | json a    -> forM_ files' $ \file -> doOneJson a file (file <.> "json")
+     | otherwise -> forM_ files' $ \file -> doOneHtml a file (file <.> "html")
 argsToOutput a@Args{files = [fin], outputFile = Just fout} =
   if | json a    -> doOneJson a fin fout
      | otherwise -> doOneHtml a fin fout
diff --git a/src/Eventlog/Data.hs b/src/Eventlog/Data.hs
--- a/src/Eventlog/Data.hs
+++ b/src/Eventlog/Data.hs
@@ -1,7 +1,7 @@
 {-# LANGUAGE OverloadedStrings #-}
 module Eventlog.Data (generateJson, generateJsonValidate ) where
 
-import Prelude hiding (print, readFile)
+import Prelude hiding (readFile)
 import Data.Aeson (Value(..), (.=), object)
 
 import Eventlog.Args (Args(..))
diff --git a/src/Eventlog/Events.hs b/src/Eventlog/Events.hs
--- a/src/Eventlog/Events.hs
+++ b/src/Eventlog/Events.hs
@@ -21,13 +21,14 @@
 import Data.Time
 import Data.Time.Clock.POSIX
 import qualified Data.Map as Map
-import Data.Vector.Unboxed (Vector, (!?))
+import Data.Vector.Unboxed (Vector, (!?), toList)
 import Data.Maybe
 import Data.Version
 import Text.ParserCombinators.ReadP
 import Control.Monad
 import Data.Char
 import System.IO
+import qualified Data.Trie.Map as Trie
 
 type PartialHeader = Int -> Header
 
@@ -73,7 +74,10 @@
 data EL = EL
   { pargs :: !(Maybe [String])
   , ident :: Maybe (Version, String)
+  , samplingRate :: !(Maybe Word64)
+  , heapProfileType :: !(Maybe HeapProfBreakdown)
   , ccMap :: !(Map.Map Word32 CostCentre)
+  , ccsMap :: CCSMap
   , clocktimeSec :: !Word64
   , samples :: !(Maybe FrameEL)
   , frames :: ![FrameEL]
@@ -83,6 +87,24 @@
 
 data FrameEL = FrameEL Word64 [Sample] deriving Show
 
+data CCSMap = CCSMap (Trie.TMap Word32 CCStack) Int deriving Show
+
+data CCStack = CCStack { ccsId :: Int, ccsName :: Text } deriving Show
+
+getCCSId :: EL -> Vector Word32 -> (CCStack, EL)
+getCCSId el@EL { ccsMap = (CCSMap trie uniq), ccMap = ccMap } k  =
+  let kl = toList k
+  in case Trie.lookup kl trie of
+        Just n -> (n, el)
+        Nothing ->
+          let new_stack = CCStack uniq name
+          in (new_stack, el { ccsMap = CCSMap (Trie.insert kl new_stack trie) (uniq + 1) })
+  where
+    name = fromMaybe "MAIN" $ do
+             cid <- (k !? 0)
+             CC{label, modul} <- Map.lookup cid ccMap
+             return $ modul <> "." <> label
+
 data CostCentre = CC { cid :: Word32
                      , label :: Text
                      , modul :: Text
@@ -92,6 +114,8 @@
 initEL t = EL
   { pargs = Nothing
   , ident = Nothing
+  , samplingRate = Nothing
+  , heapProfileType = Nothing
   , clocktimeSec = 0
   , samples = Nothing
   , frames = []
@@ -99,6 +123,7 @@
   , start = t
   , end = 0
   , ccMap = Map.empty
+  , ccsMap =  CCSMap Trie.empty 0
   }
 
 foldEvents :: Args -> [Event] -> EL
@@ -123,13 +148,18 @@
       ProgramArgs _ as -> addArgs as
       WallClockTime _ s _ -> addClocktime s
       -- Profiling Events
-      HeapProfBegin {} -> addFrame t
+      HeapProfBegin { heapProfSamplingPeriod, heapProfBreakdown } -> addHeapProfBegin heapProfSamplingPeriod heapProfBreakdown
       HeapProfCostCentre cid l m loc _  -> addCostCentre cid (CC cid l m loc)
       HeapProfSampleBegin {} -> addFrame t
+      HeapBioProfSampleBegin { heapProfSampleTime = t' } -> addFrame t'
       HeapProfSampleCostCentre _hid r d s -> addCCSample r d s
       HeapProfSampleString _hid res k -> addSample (Sample k (fromIntegral res))
       _ -> id
 
+
+addHeapProfBegin :: Word64 -> HeapProfBreakdown -> EL -> EL
+addHeapProfBegin sr hptype el = el { samplingRate = Just sr, heapProfileType = Just hptype }
+
 addIdent :: String -> EL -> EL
 addIdent s el = el { ident = parseIdent s }
 
@@ -150,11 +180,10 @@
 
 addCCSample :: Word64 -> Word8 -> Vector Word32 -> EL -> EL
 addCCSample res _sd st el =
-  fromMaybe (addSample (Sample "NONE" (fromIntegral res)) el) $ do
-  cid <- st !? 0
-  CC{label, modul} <- Map.lookup cid (ccMap el)
-  let fmtl = modul <> "." <> label
-  return $ addSample (Sample fmtl (fromIntegral res)) el
+  let (CCStack stack_id tid, el') = getCCSId el st
+      -- TODO: Can do better than this by differentiating normal samples form stack samples
+      sample_string = (T.pack $ "(" ++ show stack_id ++ ") ") <> tid
+  in addSample (Sample sample_string (fromIntegral res)) el'
 
 
 addClocktime :: Word64 -> EL -> EL
@@ -221,6 +250,16 @@
 elHeader EL{..} =
   let title = maybe "" (T.unwords . map T.pack) pargs
       date = formatDate clocktimeSec
-  in Header title date "" ""
-
+      profileType = ppHeapProfileType heapProfileType
+      ppSamplingRate = T.pack . maybe "<Not available>" (show . fromNano) $ samplingRate
+  in Header title date profileType ppSamplingRate "" ""
 
+ppHeapProfileType :: Maybe HeapProfBreakdown -> Text
+ppHeapProfileType (Just HeapProfBreakdownCostCentre) = "Cost centre profiling (implied by -hc)"
+ppHeapProfileType (Just HeapProfBreakdownModule) = "Profiling by module (implied by -hm)"
+ppHeapProfileType (Just HeapProfBreakdownClosureDescr) = "Profiling by closure description (implied by -hd)"
+ppHeapProfileType (Just HeapProfBreakdownTypeDescr) = "Profiling by type (implied by -hy)"
+ppHeapProfileType (Just HeapProfBreakdownRetainer) = "Retainer profiling (implied by -hr)"
+ppHeapProfileType (Just HeapProfBreakdownBiography) = "Biographical profiling (implied by -hb)"
+ppHeapProfileType (Just HeapProfBreakdownClosureType) = "Basic heap profile (implied by -hT)"
+ppHeapProfileType Nothing = "<Not available>"
diff --git a/src/Eventlog/HeapProf.hs b/src/Eventlog/HeapProf.hs
--- a/src/Eventlog/HeapProf.hs
+++ b/src/Eventlog/HeapProf.hs
@@ -24,7 +24,7 @@
         zipWith header [sJOB, sDATE, sSAMPLE_UNIT, sVALUE_UNIT] hs
       fs = chunkSamples ss
   in  (
-        Header job date smpU valU
+        Header job date (pack "") (pack "") smpU valU
       ,  fs
       )
 
diff --git a/src/Eventlog/HtmlTemplate.hs b/src/Eventlog/HtmlTemplate.hs
--- a/src/Eventlog/HtmlTemplate.hs
+++ b/src/Eventlog/HtmlTemplate.hs
@@ -84,6 +84,16 @@
 
     H.div ! class_ "row" $ do
       H.div ! class_ "column" $ do
+        "Type of profile: "
+        code $ toHtml $ hHeapProfileType header'
+
+    H.div ! class_ "row" $ do
+      H.div ! class_ "column" $ do
+        "Sampling rate in seconds: "
+        code $ toHtml $ hSamplingRate header'
+
+    H.div ! class_ "row" $ do
+      H.div ! class_ "column" $ do
         button ! class_ "tablink button-black" ! onclick "changeTab('areachart', this)" ! A.id "defaultOpen" $ "Area Chart"
         button ! class_ "tablink button-black" ! onclick "changeTab('normalizedchart', this)" $ "Normalized"
         button ! class_ "tablink button-black" ! onclick "changeTab('streamgraph', this)" $ "Streamgraph"
diff --git a/src/Eventlog/Types.hs b/src/Eventlog/Types.hs
--- a/src/Eventlog/Types.hs
+++ b/src/Eventlog/Types.hs
@@ -7,10 +7,12 @@
   Header
   { hJob         :: Text
   , hDate        :: Text
+  , hHeapProfileType :: Text
+  , hSamplingRate :: Text
   , hSampleUnit  :: Text
   , hValueUnit   :: Text
   , hCount       :: Int
-  }
+  } deriving Show
 
 data Sample = Sample Text Double deriving Show
 
@@ -19,4 +21,4 @@
 -- | A trace we also want to show on the graph
 data Trace = Trace Double Text deriving Show
 
-data ProfData = ProfData Header (Map Text (Double, Double)) [Frame] [Trace]
+data ProfData = ProfData Header (Map Text (Double, Double)) [Frame] [Trace] deriving Show