diff --git a/Account.hs b/Account.hs
index 8bd22add8..2ce693d2b 100644
--- a/Account.hs
+++ b/Account.hs
@@ -12,7 +12,7 @@ import Ledger
 
 
 -- an Account caches an account's name, balance (including sub-accounts)
--- and transactions (not including sub-accounts)
+-- and transactions (excluding sub-accounts)
 data Account = Account {
       aname :: AccountName, 
       atransactions :: [EntryTransaction],
@@ -24,13 +24,15 @@ instance Show Account where
 
 nullacct = Account "" [] nullamt
 
-mkAccount :: Ledger -> AccountName -> Account
-mkAccount l a = 
+ledgerAccount :: Ledger -> AccountName -> Account
+ledgerAccount l a = 
     Account 
     a 
     (transactionsInAccountNamed l a) 
     (aggregateBalanceInAccountNamed l a)
 
+-- queries
+
 balanceInAccountNamed :: Ledger -> AccountName -> Amount
 balanceInAccountNamed l a = 
     sumEntryTransactions (transactionsInAccountNamed l a)
@@ -47,64 +49,58 @@ aggregateTransactionsInAccountNamed :: Ledger -> AccountName -> [EntryTransactio
 aggregateTransactionsInAccountNamed l a = 
     ledgerTransactionsMatching (["^" ++ a ++ "(:.+)?$"], []) l
 
--- a tree of Accounts
-
+-- build a tree of Accounts
 addDataToAccountNameTree :: Ledger -> Tree AccountName -> Tree Account
 addDataToAccountNameTree l ant = 
     Node 
-    (mkAccount l $ root ant) 
+    (ledgerAccount l $ root ant) 
     (map (addDataToAccountNameTree l) $ branches ant)
 
--- would be straightforward except we want to elide boring accounts when
--- displaying account trees:
--- a (0 txns, only 1 subacct)
---   b (another boring acct.)
---     c
---       d
--- becomes:
--- a:b:c
---   d
-showAccountTree :: Ledger -> Int -> Int -> Tree Account -> String
-showAccountTree _ 0 _ _ = ""
-showAccountTree l maxdepth indentlevel t
-    -- if this acct is boring, don't show it (unless this is as deep as we're going)
---     | (boringacct && (maxdepth > 1)) = subacctsindented 0
+-- balance report support
+--
+-- some examples, ignoring the issue of eliding boring accounts
+-- here is a sample account tree:
+--
+-- assets
+--  cash
+--  checking
+--  saving
+-- equity
+-- expenses
+--  food
+--  shelter
+-- income
+--  salary
+-- liabilities
+--  debts
+--
+-- standard balance command shows all top-level accounts:
+--
+-- > ledger bal
+-- $ assets      
+-- $ equity
+-- $ expenses    
+-- $ income      
+-- $ liabilities 
+--
+-- with an account pattern, show only the ones with matching names:
+--
+-- > ledger bal asset
+-- $ assets      
+--
+-- with -s, show all subaccounts of matched accounts:
+--
+-- > ledger -s bal asset
+-- $ assets      
+-- $  cash       
+-- $  checking   
+-- $  saving
 
-    -- otherwise show normal indented account name with balance
-    -- if this acct has one or more boring parents, prepend their names
-    | otherwise = 
-        bal ++ "  " ++ indent ++ parentnames ++ leafname ++ "\n" ++ (subacctsindented 1)
-
-    where
-      boringacct = isBoringAccount2 l name
-      boringparents = takeWhile (isBoringAccount2 l) $ parentAccountNames name
-      bal = printf "%20s" $ show $ abalance $ root t
-      indent = replicate (indentlevel * 2) ' '
-      parentnames = concatMap (++ ":") $ map accountLeafName boringparents
-      leafname = accountLeafName name
-      name = aname $ root t
-      subacctsindented i = 
-          case maxdepth > 1 of
-            True -> concatMap (showAccountTree l (maxdepth-1) (indentlevel+i)) $ branches t
-            False -> ""
-
-isBoringAccount :: Tree Account -> Bool
-isBoringAccount at = 
-    (length txns == 0) && ((length subaccts) == 1) && (not $ name == "top")
-        where
-          a = root at
-          name = aname a
-          txns = atransactions a
-          subaccts = branches at
-
-isBoringAccount2 :: Ledger -> AccountName -> Bool
-isBoringAccount2 l a
-    | a == "top" = False
-    | (length txns == 0) && ((length subs) == 1) = True
-    | otherwise = False
-    where
-      txns = transactionsInAccountNamed l a
-      subs = subAccountNamesFrom (ledgerAccountNames l) a
+showLedgerAccounts :: Ledger -> [String] -> Bool -> Int -> String
+showLedgerAccounts l acctpats showsubs maxdepth = 
+    concatMap 
+    (showAccountTree l) 
+    (branches (ledgerAccountTreeMatching l acctpats showsubs maxdepth))
 
 ledgerAccountTreeMatching :: Ledger -> [String] -> Bool -> Int -> Tree Account
 ledgerAccountTreeMatching l [] showsubs maxdepth = 
@@ -114,8 +110,65 @@ ledgerAccountTreeMatching l acctpats showsubs maxdepth =
     filterAccountNameTree acctpats showsubs maxdepth $ 
     ledgerAccountNameTree l
 
-showLedgerAccounts :: Ledger -> [String] -> Bool -> Int -> String
-showLedgerAccounts l acctpats showsubs maxdepth = 
-    concatMap 
-    (showAccountTree l 999 0) 
-    (branches (ledgerAccountTreeMatching l acctpats showsubs maxdepth))
+-- when displaying an account tree, we elide boring accounts.
+-- 1. leaf accounts and branches with 0 balance or 0 transactions are omitted
+-- 2. inner accounts with 0 transactions and 1 subaccount are displayed as
+--    a prefix of the sub
+--
+-- so, for example:
+--
+-- a (0 txns)
+--   b (0 txns)
+--     c
+--       d
+-- e (0 txns)
+--   f
+--   g
+-- h (0 txns)
+--   i (0 balance)
+--
+-- displays as:
+--
+-- a:b:c
+--   d
+-- e
+--   f
+--   g
+showAccountTree :: Ledger -> Tree Account -> String
+showAccountTree l = showAccountTree' l 0 . interestingAccountsFrom
+    
+interestingAccountsFrom :: Tree Account -> Tree Account
+interestingAccountsFrom =
+    treefilter hastxns . treefilter hasbalance
+    where 
+      hasbalance = (/= 0) . abalance
+      hastxns = (> 0) . length . atransactions
+
+showAccountTree' l indentlevel t
+    -- if this acct is boring, don't show it (unless this is as deep as we're going)
+    | isBoringAccount l name = subacctsindented 0
+
+    -- otherwise show normal indented account name with balance
+    -- if this acct has one or more boring parents, prepend their names
+    | otherwise = 
+        bal ++ "  " ++ indent ++ prefix ++ leafname ++ "\n" ++ (subacctsindented 1)
+
+    where
+      subacctsindented i = 
+          concatMap (showAccountTree' l (indentlevel+i)) $ branches t
+      bal = printf "%20s" $ show $ abalance $ root t
+      indent = replicate (indentlevel * 2) ' '
+      prefix = concatMap (++ ":") $ map accountLeafName boringparents
+      boringparents = takeWhile (isBoringAccount l) $ parentAccountNames name
+      leafname = accountLeafName name
+      name = aname $ root t
+
+isBoringAccount :: Ledger -> AccountName -> Bool
+isBoringAccount l a
+    | a == "top" = False
+    | (length txns == 0) && ((length subs) == 1) = True
+    | otherwise = False
+    where
+      txns = transactionsInAccountNamed l a
+      subs = subAccountNamesFrom (ledgerAccountNames l) a
+
diff --git a/AccountName.hs b/AccountName.hs
index 328437876..8141cc55c 100644
--- a/AccountName.hs
+++ b/AccountName.hs
@@ -76,12 +76,6 @@ accountNameTreeFrom accts =
           accountsFrom as = [Node a (accountsFrom $ subs a) | a <- as]
           subs = (subAccountNamesFrom accts)
 
-showAccountNameTree :: Tree AccountName -> String
-showAccountNameTree t =
-    topacct  ++ "\n" ++ concatMap showAccountNameTree (branches t)
-        where
-          topacct = indentAccountName 0 $ root t
-
 filterAccountNameTree :: [String] -> Bool -> Int -> Tree AccountName -> Tree AccountName
 filterAccountNameTree pats keepsubs maxdepth =
     treefilter (\a -> matchpats a || (keepsubs && issubofmatch a)) .
diff --git a/TODO b/TODO
index 1c569e607..3c3f3550f 100644
--- a/TODO
+++ b/TODO
@@ -1,102 +1,11 @@
-* feature: balance report account matching
-
-sample account tree:
-
-assets
- cash
- checking
- saving
-equity
-expenses
- food
- shelter
-income
- salary
-liabilities
- debts
-
-standard balance command shows all top-level accounts:
-
-> ledger bal
-$ assets      
-$ equity
-$ expenses    
-$ income      
-$ liabilities 
-
-with an account pattern, show only the ones with matching names:
-
-> ledger bal asset
-$ assets      
-
-with -s, show all subaccounts of matched accounts:
-
-> ledger -s bal asset
-$ assets      
-$  cash       
-$  checking   
-$  saving
-
-again:
-
-> ledger bal a
-$ assets      
-$  cash       
-$  saving
-$ income      
-$  salary     
-$ liabilities 
-
-and including subaccounts:
-
-> ledger -s bal a
-$ assets      
-$  cash       
-$  checking   
-$  saving
-$ income      
-$  salary     
-$ liabilities 
-$  debts
-
-but also, elide boring accounts whenever possible, so if savings is 0 and
-income/liabilities have no transactions the above would be displayed as:
-
-> ledger -s bal a
-$ assets      
-$  cash       
-$  checking   
-$ income:salary
-$ liabilities:debts
-
-algorithm:
-
-1 filter account tree by name, keeping any necessary parents
-2 add subaccounts if -s
-3 display account tree, eliding boring accounts
-
-elide boring accounts
-
-
-
-
-
-
-
-
-
-
-
-
 optimization: add CookedLedger caching acct txns, boring status etc.
  refactor apis
 
-
-
 speed
  profile, refactor, optimize
 
 basic features
+ , in thousands
  -f -
  print
  -j and -J graph data output
diff --git a/Tests.hs b/Tests.hs
index c1223a750..677d696f2 100644
--- a/Tests.hs
+++ b/Tests.hs
@@ -125,6 +125,10 @@ ledger7_str = "\
 \    assets:cash                                $4.82\n\
 \    equity:opening balances                         \n\
 \\n\
+\2007/01/01 * opening balance\n\
+\    income:interest                                $-4.82\n\
+\    equity:opening balances                         \n\
+\\n\
 \2007/01/02 * ayres suites\n\
 \    expenses:vacation                        $179.92\n\
 \    assets:checking                                 \n\