diff --git a/lib/debug.js b/lib/debug.js
index 969d1222..c70231c9 100644
--- a/lib/debug.js
+++ b/lib/debug.js
@@ -4,6 +4,7 @@
  */
 
 var tty = require('tty');
+var util = require('util');
 
 /**
  * Expose `debug()` as the module.
@@ -16,7 +17,8 @@ module.exports = debug;
  */
 
 var names = []
-  , skips = [];
+  , skips = []
+  , showPID = false;
 
 (process.env.DEBUG || '')
   .split(/[\s,]+/)
@@ -25,10 +27,25 @@ var names = []
     if (name[0] === '-') {
       skips.push(new RegExp('^' + name.substr(1) + '$'));
     } else {
-      names.push(new RegExp('^' + name + '$'));
+      if (name == 'PID') {
+        showPID = true;
+      } else {
+        names.push(new RegExp('^' + name + '$'));
+      }
     }
   });
 
+function isEnabled(name) {
+  var disabled = skips.some(function(re) {
+    return re.test(name);
+  });
+  if (disabled) return false;
+  return names.some(function(re) {
+    return re.test(name);
+  });
+}
+
+
 /**
  * Colors.
  */
@@ -64,6 +81,16 @@ function color() {
   return colors[prevColor++ % colors.length];
 }
 
+function c3(c) {
+  return '\033[3' + c + 'm';
+}
+
+function c9(c) {
+  return '\033[9' + c + 'm';
+}
+
+var clearColor = '\033[0m';
+
 /**
  * Humanize the given `ms`.
  *
@@ -91,45 +118,72 @@ function humanize(ms) {
  * @api public
  */
 
-function debug(name) {
-  function disabled(){}
-  disabled.enabled = false;
-
-  var match = skips.some(function(re){
-    return re.test(name);
-  });
+function debug(name, kind, kindColor) {
+  var log = function disabled(){}
+  var format = util.format;
 
-  if (match) return disabled;
+  if (isEnabled(name) || (kind && isEnabled(kind + ':' + name))) {
+    if (kind && kind.length == 4) kind = kind + ' ';
 
-  match = names.some(function(re){
-    return re.test(name);
-  });
+    if (isatty) {
+      var c = color()
+        , pid = showPID ? c9(Number(process.pid) % 7) + process.pid + ' ' + c9(0) : ''
+        , knd = kind ? c9(kindColor) + kind + ' ' + c9(0) : ''
+        , pre = '  ' + pid + knd + c9(c) + name + ' ' + c3(c) + c9(0)
+        , post = ' ' + c3(c) + c9(c) + '+'
 
-  if (!match) return disabled;
-  var c = color();
+      log = function colored(fmt) {
+        var curr = new Date;
+        var ms = curr - (prev[name] || curr);
+        prev[name] = curr;
 
-  function colored(fmt) {
-    var curr = new Date;
-    var ms = curr - (prev[name] || curr);
-    prev[name] = curr;
-
-    fmt = '  \033[9' + c + 'm' + name + ' '
-      + '\033[3' + c + 'm\033[90m'
-      + fmt + '\033[3' + c + 'm'
-      + ' +' + humanize(ms) + '\033[0m';
+        fmt = new Date().toISOString() + pre + fmt + post + humanize(ms) + clearColor;
+        process.stderr.write(format.apply(this, arguments) + "\n");
+      }
+    } else {
+      var pid = showPID ? process.pid + ' ' : ''
+        , knd = kind ? kind + ' ' : ''
+        , pre = pid + knd
+        , post = ' ' + name + ' '
+
+      log = function plain(fmt) {
+        fmt = pre + new Date().toISOString() + post + fmt;
+        process.stderr.write(format.apply(this, arguments) + "\n");
+      }
+    }
 
-    console.error.apply(this, arguments);
+    log.enabled = true;
   }
 
-  function plain(fmt) {
-    fmt = new Date().toUTCString()
-      + ' ' + name + ' ' + fmt;
-    console.error.apply(this, arguments);
+  if (!kind) {
+    log.error = debug(name, 'ERROR', 1);
+    log.debug = debug(name, 'DEBUG', 2);
+    log.warn  = debug(name, 'WARN',  3);
+    log.info  = debug(name, 'INFO',  4);
+    log.trace = debug(name, 'TRACE', 5);
   }
 
-  colored.enabled = plain.enabled = true;
+  return log;
+}
 
-  return isatty
-    ? colored
-    : plain;
+if (!Date.prototype.toISOString) {
+  (function() {
+    function pad(number) {
+      var r = String(number);
+      if (r.length === 1) {
+        r = '0' + r;
+      }
+      return r;
+    }
+    Date.prototype.toISOString = function() {
+      return this.getUTCFullYear()
+        + '-' + pad( this.getUTCMonth() + 1 )
+        + '-' + pad( this.getUTCDate() )
+        + 'T' + pad( this.getUTCHours() )
+        + ':' + pad( this.getUTCMinutes() )
+        + ':' + pad( this.getUTCSeconds() )
+        + '.' + String( (this.getUTCMilliseconds()/1000).toFixed(3) ).slice( 2, 5 )
+        + 'Z';
+    };
+  }());
 }