diff --git a/experiments/scrollapp.nim b/experiments/scrollapp.nim
index 7b7ce8e..f9c8ccb 100644
--- a/experiments/scrollapp.nim
+++ b/experiments/scrollapp.nim
@@ -1,17 +1,14 @@
 
-import vdom, karax, karaxdsl, jdict, jstrutils
+import vdom, karax, karaxdsl, jdict, jstrutils, components
 
 type
   Filter = enum
     all, active, completed
 
-const
-  WindowSize = 50 # overestimating it does not harm
-
 var
   entries: seq[(cstring, bool)]
   visibleA = 0
-  visibleB = 10_000
+  visibleB = 10
   selectedEntry = -1
   filter: Filter
 
@@ -52,34 +49,15 @@ proc toChecked(checked: bool): cstring =
 proc selected(v: Filter): cstring =
   (if filter == v: cstring"selected" else: cstring(nil))
 
-when false:
-  proc entry(id: int, d: cstring; completed, selected: bool): proc (): VNode =
-    var lastid: type(id)
-    var lastd: type(d)
-    var lastCompleted: type(completed)
-    var lastSelected: type(selected)
-    proc inner(): VNode =
-      if lastid != id or lastd != d or lastCompleted != completed or lastSelected != selected:
-        result = logic(id, d, completed, selected)
-        lastid = id
-        lastd = d
-        lastCompleted = completed
-        lastSelected = selected
-
-    result = inner
-
-proc lazyEntry(args: seq[VNode]): VNode =
-  let id = args[0].intValue
-  let d = args[1].text
-  let completed = args[2].intValue != 0
-  let selected = args[3].intValue != 0
+proc createEntry(id: int; d: cstring;
+                 completed: bool, selected: bool): VNode {.component.} =
   result = buildHtml(tr):
     li(class=toClass(completed), key = id):
       if not selected:
         tdiv(class = "view"):
           input(class = "toggle", `type` = "checkbox", checked = toChecked(completed),
                 onclick=toggleEntry, key = id)
-          label(onDblClick=editHandler, key = id):
+          label(onclick=editHandler, key = id):
             text d
           button(class = "destroy", key = id, onclick = removeHandler)
       else:
@@ -87,9 +65,6 @@ proc lazyEntry(args: seq[VNode]): VNode =
           onfocusLost = focusLost,
           onenter = editEntry, value = d, setFocus)
 
-proc createEntry(id: int; d: cstring; completed, selected: bool): VNode =
-  result = thunk(lazyEntry, id, d, completed, selected)
-
 proc myscroll(ev: Event; n: VNode) =
   kout cstring"scrolling event here"
 
@@ -105,10 +80,6 @@ proc createDom(): VNode =
         input(class = "toggle-all", `type` = "checkbox", name = "toggle")
         label(`for` = "toggle-all", onclick = onAllDone):
           text "Mark all as complete"
-        tdiv(onscroll = myscroll, style = "overflow: visible; width: 0px; display: block; max-height: 1em"):
-          for i in 0..4:
-            tdiv:
-              text entries[i][0]
 
         var entriesCount = 0
         var completedCount = 0
diff --git a/src/components.nim b/src/components.nim
new file mode 100644
index 0000000..6d6a8f2
--- /dev/null
+++ b/src/components.nim
@@ -0,0 +1,103 @@
+## Components in Karax are built by the ``.component`` macro annotation.
+
+import macros, jdict, dom, vdom, tables, strutils
+
+var
+  vcomponents* = newJDict[cstring, proc(args: seq[VNode]): VNode]()
+  dcomponents* = newJDict[cstring, proc(args: seq[VNode]): Node]()
+
+type
+  ComponentKind* {.pure.} = enum
+    None,
+    VNode,
+    Node
+
+var
+  allcomponents {.compileTime.} = initTable[string, ComponentKind]()
+
+proc isComponent*(x: string): ComponentKind {.compileTime.} =
+  allcomponents.getOrDefault(x)
+
+proc unpack(symbolicType: NimNode; index: int): NimNode {.compileTime.} =
+  #let t = symbolicType.getTypeImpl
+  let t = repr(symbolicType)
+  case t
+  of "cstring":
+    result = quote do:
+      args[`index`].text
+  of "int", "VKey":
+    result = quote do:
+      args[`index`].intValue
+  of "bool":
+    result = quote do:
+      args[`index`].intValue != 0
+  elif t.endsWith"Kind":
+    result = quote do:
+      `symbolicType`(args[`index`].intValue)
+  else:
+    # just pass it along, maybe there is some conversion for it:
+    result = quote do:
+      args[`index`]
+
+proc newname*(n: NimNode): NimNode =
+  if n.kind == nnkPostfix:
+    n[1] = newname(n[1])
+    result = n
+  elif n.kind == nnkSym:
+    result = ident($n.symbol)
+  else:
+    result = n
+
+macro component*(prc: untyped): untyped =
+  ## A component takes an proc body and registers it as a component to the
+  ## virtual dom.
+  var n = prc.copyNimNode
+  for i in 0..6: n.add prc[i].copyNimTree
+  expectKind(n, nnkProcDef)
+  if n[0].kind == nnkEmpty:
+    error("please pass a non anonymous proc")
+  let name = n[0]
+  let params = params(n)
+  let rettype = repr params[0]
+  var isvirtual = ComponentKind.None
+  if rettype == "VNode":
+    isvirtual = ComponentKind.VNode
+  elif rettype == "Node":
+    isvirtual = ComponentKind.Node
+  else:
+    error "component must return VNode or Node"
+  n[0] = ident("inner" & $name)
+  var unpackCall = newCall(n[0])
+  var counter = 0
+  for i in 1.. <params.len:
+    let param = params[i]
+    let L = param.len
+    let typ = param[L-2]
+    for j in 0 .. L-3:
+      unpackCall.add unpack(typ, counter)
+      inc counter
+
+  template vwrapper(wname, nameStrLit, unpackCall) {.dirty.} =
+    proc wname*(args: seq[VNode]): VNode =
+      unpackCall
+    vcomponents[cstring(nameStrLit)] = wname
+
+  template dwrapper(wname, nameStrLit, unpackCall) {.dirty.} =
+    proc wname(args: seq[VNode]): Node =
+      unpackCall
+    dcomponents[cstring(nameStrLit)] = wname
+
+  result = newTree(nnkStmtList, n)
+  if isvirtual == ComponentKind.VNode:
+    result.add getAst(vwrapper(newname name, newLit($name), unpackCall))
+  else:
+    result.add getAst(dwrapper(newname name, newLit($name), unpackCall))
+  allcomponents[$name] = isvirtual
+  when defined(debugKaraxDsl):
+    echo repr result
+
+when isMainModule:
+  proc foo(x, y: int, b: bool; s: cstring): VNode {.component.} =
+    discard
+
+
diff --git a/src/dom.nim b/src/dom.nim
index 9414c89..87d1cfc 100644
--- a/src/dom.nim
+++ b/src/dom.nim
@@ -520,6 +520,8 @@ proc item*(list: TouchList, i: int): Touch
 
 {.pop.}
 
+proc setAttr*(n: Node; key, val: cstring) {.importcpp: "#.setAttribute(@)".}
+
 var
   window* {.importc, nodecl.}: Window
   document* {.importc, nodecl.}: Document
diff --git a/src/karax.nim b/src/karax.nim
index f0f70dd..80d67c8 100644
--- a/src/karax.nim
+++ b/src/karax.nim
@@ -1,6 +1,6 @@
 # Simple lib to write JS UIs
 
-import dom, vdom, jstrutils
+import dom, vdom, jstrutils, components, jdict
 
 export dom.Event, dom.cloneNode, dom
 
@@ -68,8 +68,12 @@ proc isElementInViewport(el: Node; h: var int): bool =
 proc vnodeToDom(n: VNode): Node =
   if n.kind == VNodeKind.text:
     result = document.createTextNode(n.text)
-  elif n.kind == VNodeKind.thunk:
-    return vnodeToDom(n.callThunk)
+  elif n.kind == VNodeKind.vthunk:
+    let x = callThunk(vcomponents[n.text], n)
+    return vnodeToDom(x)
+  elif n.kind == VNodeKind.dthunk:
+    let x = callThunk(dcomponents[n.text], n)
+    return x
   else:
     result = document.createElement(toTag[n.kind])
     for k in n:
@@ -85,7 +89,7 @@ proc vnodeToDom(n: VNode): Node =
     result.key = n.key
   for k, v in attrs(n):
     if v != nil:
-      result.setAttribute(k, v)
+      result.setAttr(k, v)
   let myn = n
   for e, h in items(n.events):
     proc wrapper(): proc (ev: Event) =
@@ -136,23 +140,26 @@ proc equals(a, b: VNode): bool =
   if a.key != b.key: return false
   if a.kind == VNodeKind.text:
     if a.text != b.text: return false
-  elif a.kind == VNodeKind.thunk:
-    if a.thunk != b.thunk: return false
+  elif a.kind == VNodeKind.vthunk or a.kind == VNodeKind.dthunk:
+    if a.text != b.text: return false
     if a.len != b.len: return false
     for i in 0..<a.len:
       if not equals(a[i], b[i]): return false
   if not sameAttrs(a, b): return false
   if a.class != b.class: return false
   # XXX test event listeners here?
-  # --> maybe give nodes a hash?
   return true
 
 proc equalsTree(a, b: VNode): bool =
-  if not a.validHash:
-    a.calcHash()
-  if not b.validHash:
-    b.calcHash()
-  return a.hash == b.hash
+  when false:
+    # hashing is too fragile now with component support:
+    if not a.validHash:
+      a.calcHash()
+    if not b.validHash:
+      b.calcHash()
+    return a.hash == b.hash
+  else:
+    return eq(a, b)
 
 proc updateElement(parent, current: Node, newNode, oldNode: VNode) =
   if not equals(newNode, oldNode):
@@ -177,12 +184,14 @@ proc updateElement(parent, current: Node, newNode, oldNode: VNode) =
           current.removeChild(current.lastChild)
     else:
       var commonPrefix = 0
-      while commonPrefix < minLength and equalsTree(newNode[commonPrefix], oldNode[commonPrefix]):
+      while commonPrefix < minLength and
+          equalsTree(newNode[commonPrefix], oldNode[commonPrefix]):
         inc commonPrefix
 
       var oldPos = oldLength - 1
       var newPos = newLength - 1
-      while oldPos >= commonPrefix and newPos >= commonPrefix and equalsTree(newNode[newPos], oldNode[oldPos]):
+      while oldPos >= commonPrefix and newPos >= commonPrefix and
+          equalsTree(newNode[newPos], oldNode[oldPos]):
         dec oldPos
         dec newPos
 
@@ -254,18 +263,6 @@ proc redraw*() =
 proc init*() =
   reqFrame(dodraw)
 
-#proc prepend*(parent, kid: Element) =
-#  parent.insertBefore(kid, parent.firstChild)
-#  prependChild(parent, kid)
-
-proc suffix*(s, prefix: cstring): cstring =
-  if s.startsWith(prefix):
-    result = s.substr(prefix.len)
-  else:
-    kout(cstring"bug! " & s & cstring" does not start with " & prefix)
-
-proc suffixAsInt*(s, prefix: cstring): int = parseInt(suffix(s, prefix))
-
 proc scrollTop*(e: Node): int {.importcpp: "#.scrollTop", nodecl.}
 proc offsetHeight*(e: Node): int {.importcpp: "#.offsetHeight", nodecl.}
 proc offsetTop*(e: Node): int {.importcpp: "#.offsetTop", nodecl.}
@@ -291,8 +288,6 @@ proc setOnchanged*(e: VNode; action: EventHandler) =
 proc setOnscroll*(e: VNode; action: EventHandler) =
   onImpl EventKind.onscroll
 
-#proc ceil(f: float): int {.importc: "Math.ceil", nodecl.}
-
 proc setOnscroll*(action: proc(min, max: VKey; diff: int)) =
   var oldY = window.pageYOffset
 
@@ -321,98 +316,6 @@ proc setOnHashChange*(action: proc (hashPart: cstring)) =
     redraw()
   onhashchange = wrapper
 
-var
-  linkCounter: int
-
-proc link*(id: int): VNode =
-  result = newVNode(VNodeKind.anchor)
-  result.setAttr("href", "#")
-  inc linkCounter
-  result.setAttr("id", $linkCounter & ":" & $id)
-
-proc link*(action: EventHandler): VNode =
-  result = newVNode(VNodeKind.anchor)
-  result.setAttr("href", "#")
-  result.setOnclick action
-
-when false:
-  proc button*(caption: cstring; action: EventHandler; disabled=false): VNode =
-    result = newVNode(VNodeKind.button)
-    result.add text(caption)
-    if action != nil:
-      result.setOnClick action
-    if disabled:
-      result.setAttr("disabled", "true")
-
-proc select*(choices: openarray[cstring]): VNode =
-  result = newVNode(VNodeKind.select)
-  var i = 0
-  for c in choices:
-    result.add tree(VNodeKind.option, [(cstring"value", toCstr(i))], text(c))
-    inc i
-
-proc select*(choices: openarray[(int, cstring)]): VNode =
-  result = newVNode(VNodeKind.select)
-  for c in choices:
-    result.add tree(VNodeKind.option, [(cstring"value", toCstr(c[0]))], text(c[1]))
-
-var radioCounter: int
-
-proc radio*(choices: openarray[(int, cstring)]): VNode =
-  result = newVNode(VNodeKind.fieldset)
-  var i = 0
-  inc radioCounter
-  for c in choices:
-    let id = cstring"radio_" & c[1] & toCstr(i)
-    var kid = tree(VNodeKind.input, [(cstring"type", cstring"radio"),
-      (cstring"id", id), (cstring"name", cstring"radio" & toCStr(radioCounter)),
-      (cstring"value", toCStr(c[0]))])
-    if i == 0:
-      kid.setAttr(cstring"checked", cstring"checked")
-    var lab = tree(VNodeKind.label, [(cstring"for", id)], text(c[1]))
-    kid.add lab
-    result.add kid
-    inc i
-
-proc tag*(kind: VNodeKind; id=cstring(nil), class=cstring(nil)): VNode =
-  result = newVNode(kind)
-  result.id = id
-  result.class = class
-
-proc tdiv*(id=cstring(nil), class=cstring(nil)): VNode = tag(VNodeKind.tdiv, id, class)
-proc span*(id=cstring(nil), class=cstring(nil)): VNode = tag(VNodeKind.span, id, class)
-
-proc valueAsInt*(e: Node): int = parseInt(e.value)
-
-proc th*(s: cstring): VNode =
-  result = newVNode(VNodeKind.th)
-  result.add text(s)
-
-proc td*(s: string): VNode =
-  result = newVNode(VNodeKind.td)
-  result.add text(s)
-
-proc td*(s: VNode): VNode =
-  result = newVNode(VNodeKind.td)
-  result.add s
-
-proc td*(class: cstring; s: VNode): VNode =
-  result = newVNode(VNodeKind.td)
-  result.add s
-  result.class = class
-
-proc table*(class=cstring(nil), kids: varargs[VNode]): VNode =
-  result = tag(VNodeKind.table, nil, class)
-  for k in kids: result.add k
-
-proc tr*(kids: varargs[VNode]): VNode =
-  result = newVNode(VNodeKind.tr)
-  for k in kids:
-    if k.kind in {VNodeKind.td, VNodeKind.th}:
-      result.add k
-    else:
-      result.add td(k)
-
 proc getAttr(e: Node; key: cstring): cstring {.
   importcpp: "#.getAttribute(#)", nodecl.}
 
@@ -426,9 +329,6 @@ template keyeventBody() =
   redraw()
 
 proc realtimeInput*(val: cstring; action: EventHandler): VNode =
-  #let oldElem = getElementById(id)
-  #if oldElem != nil: return oldElem
-  #let newVal = if oldElem.isNil: val else: $oldElem.value
   var timer: Timeout
   proc onkeyup(ev: Event; n: VNode) =
     proc wrapper() = keyeventBody()
@@ -440,9 +340,6 @@ proc realtimeInput*(val: cstring; action: EventHandler): VNode =
   result.addEventListener(EventKind.onkeyup, onkeyup)
 
 proc enterInput*(id, val: cstring; action: EventHandler): VNode =
-  #let oldElem = getElementById(id)
-  #if oldElem != nil: return oldElem
-  #let newVal = if oldElem.isNil: val else: $oldElem.value
   proc onkeyup(ev: Event; n: VNode) =
     if ev.keyCode == 13: keyeventBody()
 
@@ -508,16 +405,13 @@ proc setupErrorHandler*(useAlert=false) =
 
 {.pop.}
 
-when false:
-  var plugins {.exportc.}: seq[(string, proc())] = @[]
-
-  proc onInput(val: cstring) =
-    kout val
-    if val == "dyn":
-      let body = getElementById("body")
-      body.prepend(tree("script", [("type", "text/javascript"), ("src", "nimcache/dyn.js")]))
-      redraw()
-    kout(plugins.len)
-    if plugins.len > 0:
-      plugins[0][1]()
+proc prepend*(parent, kid: Element) =
+  parent.insertBefore(kid, parent.firstChild)
 
+proc loadScript*(jsfilename: cstring) =
+  let body = getElementById("body")
+  let s = document.createElement("script")
+  s.setAttr "type", "text/javascript"
+  s.setAttr "src", jsfilename
+  body.prepend(s)
+  redraw()
diff --git a/src/karaxdsl.nim b/src/karaxdsl.nim
index 6b8e540..dce3034 100644
--- a/src/karaxdsl.nim
+++ b/src/karaxdsl.nim
@@ -1,5 +1,5 @@
 
-import macros, karax, vdom
+import macros, karax, vdom, components
 from strutils import startsWith, toLowerAscii
 
 const
@@ -61,11 +61,19 @@ proc tcall2(n, tmpContext: NimNode): NimNode =
     result = n
   of nnkCallKinds:
     let op = getName(n[0])
-    if isTag(op):
+    let ck = isComponent(op)
+    let isTag = isTag(op)
+    if isTag or ck != ComponentKind.None:
       let tmp = genSym(nskLet, "tmp")
+      let call = if isTag:
+                   newCall(bindSym"tree", newDotExpr(bindSym"VNodeKind", n[0]))
+                 elif ck == ComponentKind.VNode:
+                   newCall(bindSym"vthunk", newLit(op))
+                 else:
+                   newCall(bindSym"dthunk", newLit(op))
       result = newTree(
         if tmpContext == nil: nnkStmtListExpr else: nnkStmtList,
-        newLetStmt(tmp, newCall(bindSym"tree", newDotExpr(bindSym"VNodeKind", n[0]))))
+        newLetStmt(tmp, call))
       for i in 1 ..< n.len:
         # named parameters are transformed into attributes or events:
         let x = n[i]
@@ -77,7 +85,9 @@ proc tcall2(n, tmpContext: NimNode): NimNode =
             result.add newDotAsgn(tmp, key, x[1])
           else:
             result.add newCall(bindSym"setAttr", tmp, newLit(key), x[1])
-        elif x.kind == nnkIdent:
+        elif not isTag:
+          call.add x
+        elif eqIdent(x, "setFocus"):
           result.add newCall(x, tmp)
         else:
           result.add tcall2(x, tmp)
diff --git a/src/vdom.nim b/src/vdom.nim
index 0ddfc3a..2670be5 100644
--- a/src/vdom.nim
+++ b/src/vdom.nim
@@ -5,7 +5,7 @@ import shash
 
 type
   VNodeKind* {.pure.} = enum
-    text, int, bool, thunk,
+    text, int, bool, vthunk, dthunk,
     anchor,
     tdiv,
     table, tr, td, th, thead, tbody,
@@ -15,7 +15,8 @@ type
 
 const
   toTag*: array[VNodeKind, cstring] = [
-    cstring"#text", "#int", "#bool", "#thunk", "A", "DIV", "TABLE", "TR", "TD",
+    cstring"#text", "#int", "#bool", "#vthunk", "#dthunk",
+    "A", "DIV", "TABLE", "TR", "TD",
     "TH", "THEAD",
     "TBODY", "LINK",
     "SPAN", "LABEL", "BR", "SELECT", "OPTION", "FIELDSET", "INPUT", "BUTTON", "UL",
@@ -43,7 +44,6 @@ type
     # even index: key, odd index: value; done this way for memory efficiency:
     attrs: seq[cstring]
     events*: seq[(EventKind, EventHandler)]
-    thunk*: proc (args: seq[VNode]): VNode
     hash*: Hash
     validHash*: bool
 
@@ -55,23 +55,26 @@ proc vn*(i: int): VNode = VNode(kind: VNodeKind.int, key: i)
 proc vn*(b: bool): VNode = VNode(kind: VNodeKind.int, key: ord(b))
 proc vn*(x: cstring): VNode = VNode(kind: VNodeKind.text, key: -1, text: x)
 
-proc callThunk*(n: VNode): VNode =
-  assert n.kind == VNodeKind.thunk
-  result = n.thunk(n.kids)
+template callThunk*(fn: typed; n: VNode): untyped =
+  ## for internal usage only.
+  fn(n.kids)
 
-proc thunk*(cb: proc(args: seq[VNode]): VNode; args: varargs[VNode, vn]): VNode =
-  VNode(kind: VNodeKind.thunk, thunk: cb, kids: @args)
+proc vthunk*(name: cstring; args: varargs[VNode, vn]): VNode =
+  VNode(kind: VNodeKind.vthunk, text: name, kids: @args)
+
+proc dthunk*(name: cstring; args: varargs[VNode, vn]): VNode =
+  VNode(kind: VNodeKind.dthunk, text: name, kids: @args)
 
 proc eq*(a, b: VNode): bool =
   if a.kind != b.kind: return false
   if a.id != b.id: return false
   if a.class != b.class: return false
+  if a.key != b.key: return false
   if a.kind != VNodeKind.text:
     if a.kids.len != b.kids.len: return false
     for i in 0..<a.kids.len:
       if not eq(a.kids[i], b.kids[i]): return false
-  else:
-    if a.text != b.text: return false
+  if a.text != b.text: return false
   if a.attrs.len != b.attrs.len: return false
   for i in 0..<a.attrs.len:
     if a.attrs[i] != b.attrs[i]: return false