diff --git a/library/Icinga/Data/Filter/Filter.php b/library/Icinga/Data/Filter/Filter.php
index 49a78a2d2..78b06087b 100644
--- a/library/Icinga/Data/Filter/Filter.php
+++ b/library/Icinga/Data/Filter/Filter.php
@@ -2,6 +2,7 @@
 
 namespace Icinga\Data\Filter;
 
+use Icinga\Web\UrlParams;
 use Exception;
 
 /**
@@ -9,7 +10,7 @@ use Exception;
  *
  * Base class for filters (why?) and factory for the different FilterOperators
  */
-class Filter
+abstract class Filter
 {
     protected $id = '1';
 
@@ -19,6 +20,13 @@ class Filter
         return $this;
     }
 
+    abstract function toQueryString();
+
+    public function getUrlParams()
+    {
+        return UrlParams::fromQueryString($this->toQueryString());
+    }
+
     public function getById($id)
     {
         if ($id === $this->getId()) {
@@ -53,7 +61,20 @@ class Filter
      */
     public static function where($col, $filter)
     {
-        return new FilterWhere($col, $filter);
+        return new FilterExpression($col, '=', $filter);
+    }
+
+    public static function expression($col, $op, $expression)
+    {
+        switch ($op) {
+            case '=': return new FilterEqual($col, $op, $expression);
+            case '<': return new FilterLessThan($col, $op, $expression);
+            case '>': return new FilterGreaterThan($col, $op, $expression);
+            case '>=': return new FilterEqualOrGreaterThan($col, $op, $expression);
+            case '<=': return new FilterEqualOrLessThan($col, $op, $expression);
+            case '!=': return new FilterNotEqual($col, $op, $expression);
+            default: throw new \Exception('WTTTTF');
+        }
     }
 
     /**
@@ -65,7 +86,11 @@ class Filter
      */
     public static function matchAny()
     {
-        return new FilterOr(func_get_args());
+        $args = func_get_args();
+        if (count($args) === 1 && is_array($args[0])) {
+            $args = $args[0];
+        }
+        return new FilterOr($args);
     }
 
     /**
@@ -77,7 +102,11 @@ class Filter
      */
     public static function matchAll()
     {
-        return new FilterAnd(func_get_args());
+        $args = func_get_args();
+        if (count($args) === 1 && is_array($args[0])) {
+            $args = $args[0];
+        }
+        return new FilterAnd($args);
     }
 
     /**
@@ -87,9 +116,15 @@ class Filter
      *
      * @return FilterNot
      */
-    public static function not(Filter $filter)
+    public static function not()
     {
-        return new FilterNot(array($filter)); // ??
+        $args = func_get_args();
+        if (count($args) === 1) {
+            if (is_array($args[0])) {
+                $args = $args[0];
+            }
+        }
+        return new FilterNot($args);
     }
 
     /**
@@ -99,82 +134,9 @@ class Filter
      */
     public static function fromQueryString($query)
     {
-        $query = rawurldecode($query);
-        $parts = preg_split('~&~', $query, -1, PREG_SPLIT_NO_EMPTY);
-        $filters = Filter::matchAll();
-        foreach ($parts as $part) {
-            self::parseQueryStringPart($part, $filters);
-        }
-        return $filters;
+        return FilterQueryString::parse($query);
     }
 
-    /**
-     * Parse query string part
-     *
-     */
-    protected static function parseQueryStringPart($part, & $filters)
-    {
-        $negations = 0;
-
-        if (strpos($part, '=') === false) {
-
-            $key = rawurldecode($part);
-
-            while (substr($key, 0, 1) === '!') {
-                if (strlen($key) < 2) {
-                    throw new FilterException(
-                        sprintf('Got invalid filter part: "%s"', $part)
-                    );
-                }
-                $key = substr($key, 1);
-                $negations++;
-            }
-
-            $filter = Filter::where($key, true);
-
-        } else {
-            list($key, $val) = preg_split('/=/', $part, 2);
-            $key = rawurldecode($key);
-            $val = rawurldecode($val);
-
-            while (substr($key, 0, 1) === '!') {
-                if (strlen($key) < 2) {
-                    throw new FilterException(
-                        sprintf('Got invalid filter part: "%s"', $part)
-                    );
-                }
-                $key = substr($key, 1);
-                $negations++;
-            }
-
-            while (substr($key, -1) === '!') {
-                if (strlen($key) < 2) {
-                    throw new FilterException(
-                        sprintf('Got invalid filter part: "%s"', $part)
-                    );
-                }
-                $key = substr($key, 0, -1);
-                $negations++;
-            }
-
-            if (strpos($val, '|') !== false) {
-                $vals = preg_split('/\|/', $val, -1, PREG_SPLIT_NO_EMPTY);
-                $filter = Filter::matchAny();
-                foreach ($vals as $val) {
-                    $filter->addFilter(Filter::where($key, $val));
-                }
-            } else {
-                $filter = Filter::where($key, $val);
-            }
-
-        }
-
-        if ($negations % 2 === 0) {
-            $filters->addFilter($filter);
-        } else {
-            $filters->addFilter(Filter::not($filter));
-        }
-    }
 
     /**
      * We need a new Querystring-Parser
diff --git a/library/Icinga/Data/Filter/FilterAnd.php b/library/Icinga/Data/Filter/FilterAnd.php
index 02c0f12a9..61fabdb0c 100644
--- a/library/Icinga/Data/Filter/FilterAnd.php
+++ b/library/Icinga/Data/Filter/FilterAnd.php
@@ -7,7 +7,7 @@ namespace Icinga\Data\Filter;
  *
  * Binary AND, all contained filters must succeed
  */
-class FilterAnd extends FilterOperator
+class FilterAnd extends FilterChain
 {
     protected $operatorName = 'AND';
 
diff --git a/library/Icinga/Data/Filter/FilterOperator.php b/library/Icinga/Data/Filter/FilterChain.php
similarity index 93%
rename from library/Icinga/Data/Filter/FilterOperator.php
rename to library/Icinga/Data/Filter/FilterChain.php
index be7ee3f0b..4d459b1d1 100644
--- a/library/Icinga/Data/Filter/FilterOperator.php
+++ b/library/Icinga/Data/Filter/FilterChain.php
@@ -3,11 +3,11 @@
 namespace Icinga\Data\Filter;
 
 /**
- * FilterOperator
+ * FilterChain
  *
- * A FilterOperator contains a list ...
+ * A FilterChain contains a list ...
  */
-abstract class FilterOperator extends Filter
+abstract class FilterChain extends Filter
 {
     protected $filters = array();
 
@@ -45,7 +45,7 @@ abstract class FilterOperator extends Filter
         foreach ($this->filters as $key => $filter) {
             if ($filter->getId() === $id) {
                 $remove = $key;
-            } elseif ($filter instanceof FilterOperator) {
+            } elseif ($filter instanceof FilterChain) {
                 $filter->removeId($id);
             }
         }
@@ -115,7 +115,7 @@ abstract class FilterOperator extends Filter
         }
         $parts = array();
         foreach ($this->filters as $filter) {
-            if ($filter instanceof FilterOperator) {
+            if ($filter instanceof FilterChain) {
                 $parts[] = '(' . $filter . ')';
             } else {
                 $parts[] = (string) $filter;
diff --git a/library/Icinga/Data/Filter/FilterEqual.php b/library/Icinga/Data/Filter/FilterEqual.php
new file mode 100644
index 000000000..5b16b37a1
--- /dev/null
+++ b/library/Icinga/Data/Filter/FilterEqual.php
@@ -0,0 +1,11 @@
+<?php
+
+namespace Icinga\Data\Filter;
+
+class FilterEqual extends FilterExpression
+{
+    public function matches($row)
+    {
+        return (string) $row->{$this->column} === (string) $this->expression;
+    }
+}
diff --git a/library/Icinga/Data/Filter/FilterEqualOrGreaterThan.php b/library/Icinga/Data/Filter/FilterEqualOrGreaterThan.php
new file mode 100644
index 000000000..e57541e71
--- /dev/null
+++ b/library/Icinga/Data/Filter/FilterEqualOrGreaterThan.php
@@ -0,0 +1,11 @@
+<?php
+
+namespace Icinga\Data\Filter;
+
+class FilterEqualOrGreaterThan extends FilterExpression
+{
+    public function matches($row)
+    {
+        return (string) $row->{$this->column} >= (string) $this->expression;
+    }
+}
diff --git a/library/Icinga/Data/Filter/FilterEqualOrLessThan.php b/library/Icinga/Data/Filter/FilterEqualOrLessThan.php
new file mode 100644
index 000000000..47b6d1906
--- /dev/null
+++ b/library/Icinga/Data/Filter/FilterEqualOrLessThan.php
@@ -0,0 +1,21 @@
+<?php
+
+namespace Icinga\Data\Filter;
+
+class FilterEqualOrLessThan extends FilterExpression
+{
+    public function __toString()
+    {
+        return $this->column . ' <= ' . $this->expression;
+    }
+
+    public function toQueryString()
+    {
+        return $this->column . '<=' . $this->expression;
+    }
+
+    public function matches($row)
+    {
+        return (string) $row->{$this->column} <= (string) $this->expression;
+    }
+}
diff --git a/library/Icinga/Data/Filter/FilterWhere.php b/library/Icinga/Data/Filter/FilterExpression.php
similarity index 60%
rename from library/Icinga/Data/Filter/FilterWhere.php
rename to library/Icinga/Data/Filter/FilterExpression.php
index 16a73d9f8..52c70d19b 100644
--- a/library/Icinga/Data/Filter/FilterWhere.php
+++ b/library/Icinga/Data/Filter/FilterExpression.php
@@ -2,22 +2,34 @@
 
 namespace Icinga\Data\Filter;
 
-class FilterWhere extends Filter
+class FilterExpression extends Filter
 {
     protected $column;
+    protected $sign;
     protected $expression;
 
-    public function __construct($column, $expression)
+    public function __construct($column, $sign, $expression)
     {
         $this->column = $column;
+        $this->sign = $sign;
         $this->expression = $expression;
     }
 
+    public function isEmpty()
+    {
+        return false;
+    }
+
     public function getColumn()
     {
         return $this->column;
     }
 
+    public function getSign()
+    {
+        return $this->sign;
+    }
+
     public function setColumn($column)
     {
         $this->column = $column;
@@ -31,20 +43,25 @@ class FilterWhere extends Filter
 
     public function __toString()
     {
-        if (is_array($this->expression)) {
-            return $this->column . ' = ( ' . implode(' | ', $this->expression) . ' )';
-        } else {
-            return $this->column . ' = ' . $this->expression;
-        }
+        $expression = is_array($this->expression) ?
+             '( ' . implode(' | ', $this->expression) . ' )' :
+             $this->expression;
+
+        return sprintf(
+            '%s %s %s',
+            $this->column,
+            $this->sign,
+            $expression
+        );
     }
 
     public function toQueryString()
     {
-        if (is_array($this->expression)) {
-            return $this->column . '=' . implode('|', $this->expression);
-        } else {
-            return $this->column . '=' . $this->expression;
-        }
+        $expression = is_array($this->expression) ?
+             '(' . implode('|', $this->expression) . ')' :
+             $this->expression;
+
+        return $this->column . $this->sign . $expression;
     }
 
     public function matches($row)
@@ -61,12 +78,5 @@ class FilterWhere extends Filter
             $pattern = '/^' . implode('.*', $parts) . '$/';
             return (bool) preg_match($pattern, $row->{$this->column});
         }
-
-        foreach ($this->filters as $filter) {
-            if (! $filter->matches($row)) {
-                return false;
-            }
-        }
-        return true;
     }
 }
diff --git a/library/Icinga/Data/Filter/FilterGreaterThan.php b/library/Icinga/Data/Filter/FilterGreaterThan.php
new file mode 100644
index 000000000..6fd4f2b2d
--- /dev/null
+++ b/library/Icinga/Data/Filter/FilterGreaterThan.php
@@ -0,0 +1,12 @@
+<?php
+
+namespace Icinga\Data\Filter;
+
+class FilterGreaterThan extends FilterExpression
+{
+
+    public function matches($row)
+    {
+        return (string) $row->{$this->column} > (string) $this->expression;
+    }
+}
diff --git a/library/Icinga/Data/Filter/FilterLessThan.php b/library/Icinga/Data/Filter/FilterLessThan.php
new file mode 100644
index 000000000..dabccc669
--- /dev/null
+++ b/library/Icinga/Data/Filter/FilterLessThan.php
@@ -0,0 +1,21 @@
+<?php
+
+namespace Icinga\Data\Filter;
+
+class FilterLessThan extends FilterExpression
+{
+    public function __toString()
+    {
+        return $this->column . ' < ' . $this->expression;
+    }
+
+    public function toQueryString()
+    {
+        return $this->column . '<' . $this->expression;
+    }
+
+    public function matches($row)
+    {
+        return (string) $row->{$this->column} < (string) $this->expression;
+    }
+}
diff --git a/library/Icinga/Data/Filter/FilterNot.php b/library/Icinga/Data/Filter/FilterNot.php
index cbb66b407..39131b671 100644
--- a/library/Icinga/Data/Filter/FilterNot.php
+++ b/library/Icinga/Data/Filter/FilterNot.php
@@ -2,7 +2,7 @@
 
 namespace Icinga\Data\Filter;
 
-class FilterNot extends FilterOperator
+class FilterNot extends FilterChain
 {
     protected $operatorName = 'NOT';
 
@@ -26,6 +26,7 @@ class FilterNot extends FilterOperator
         if (empty($this->filters)) {
             return '';
         }
+
         foreach ($this->filters() as $filter) {
             $parts[] = $filter->toQueryString();
         }
@@ -38,11 +39,9 @@ class FilterNot extends FilterOperator
 
     public function __toString()
     {
-        $sub = Filter::matchAll();
-        var_dump($this->filters());
-        foreach ($this->filters() as $f) {
-            $sub->addFilter($f);
+        if (count($this->filters) === 1) {
+            return '! ' . $this->filters[0];
         }
-        return '! (' . $sub . ')';
+        return '! (' . implode('&', $this->filters) . ')';
     }
 }
diff --git a/library/Icinga/Data/Filter/FilterOr.php b/library/Icinga/Data/Filter/FilterOr.php
index 8531f66bf..c8cd40b70 100644
--- a/library/Icinga/Data/Filter/FilterOr.php
+++ b/library/Icinga/Data/Filter/FilterOr.php
@@ -2,7 +2,7 @@
 
 namespace Icinga\Data\Filter;
 
-class FilterOr extends FilterOperator
+class FilterOr extends FilterChain
 {
     protected $operatorName = 'OR';
 
diff --git a/library/Icinga/Data/Filter/FilterParseException.php b/library/Icinga/Data/Filter/FilterParseException.php
new file mode 100644
index 000000000..b56c6ba67
--- /dev/null
+++ b/library/Icinga/Data/Filter/FilterParseException.php
@@ -0,0 +1,9 @@
+<?php
+
+namespace Icinga\Data\Filter;
+
+use Exception;
+
+class FilterParseException extends Exception
+{
+}
diff --git a/library/Icinga/Data/Filter/FilterQueryString.php b/library/Icinga/Data/Filter/FilterQueryString.php
new file mode 100644
index 000000000..ba8af9850
--- /dev/null
+++ b/library/Icinga/Data/Filter/FilterQueryString.php
@@ -0,0 +1,240 @@
+<?php
+
+namespace Icinga\Data\Filter;
+
+class FilterQueryString
+{
+    protected $string;
+
+    protected $pos;
+
+    protected $length;
+    
+    protected function __construct()
+    {
+    }
+
+    public static function parse($string)
+    {
+        $parser = new static();
+        return $parser->parseQueryString($string);
+    }
+
+    protected function readNextKey()
+    {
+        $str = $this->readUnlessSpecialChar();
+
+        if ($str === false) {
+            return $str;
+        }
+        return rawurldecode($str);
+    }
+
+    protected function readNextValue()
+    {
+        $var = rawurldecode($this->readUnlessSpecialChar());
+        if ($var === '' && $this->nextChar() === '(') {
+            $this->readChar();
+            $var = preg_split('~\|~', $this->readUnless(')'));
+            if ($this->readChar() !== ')') {
+                $this->parseError(null, 'Expected ")"');
+            }
+        }
+        return $var;
+    }
+
+    protected function readNextExpression()
+    {
+
+        if ('' === ($key = $this->readNextKey())) {
+            return false;
+        }
+
+        $sign = $this->readChar();
+        if ($sign === false) {
+            return Filter::expression($key, '=', true);
+        }
+
+        if ($sign === '=') {
+            $last = substr($key, -1);
+            if ($last === '>' || $last === '<') {
+                $sign = $last . $sign;
+                $key = substr($key, 0, -1);
+            }
+        // TODO: Same as above for unescaped <> - do we really need this?
+        } elseif ($sign === '>' || $sign === '<' || $sign === '!') {
+            if ($this->nextChar() === '=') {
+                $sign .= $this->readChar();
+            }
+        }
+
+        $var = $this->readNextValue();
+
+        return Filter::expression($key, $sign, $var);
+    }
+
+    protected function parseError($char = null, $extraMsg = null)
+    {
+        if ($extraMsg === null) {
+            $extra = '';
+        } else {
+            $extra = ': ' . $extraMsg;
+        }
+        if ($char === null) {
+            $char = $this->string[$this->pos];
+        }
+
+        throw new FilterParseException(sprintf(
+            'Invalid filter "%s", unexpected %s at pos %d%s',
+            $this->string,
+            $char,
+            $this->pos,
+            $extra
+        ));
+    }
+
+    protected function readFilters($nestingLevel = 0, $op = '&')
+    {
+        $filters = array();
+        while ($this->pos < $this->length) {
+
+            if ($op === '!' && count($filters) === 1) {
+                break;
+            }
+            $filter = $this->readNextExpression();
+            $next = $this->readChar();
+
+
+            if ($filter === false) {
+
+                if ($next === '!') {
+                    $not = $this->readFilters($nestingLevel + 1, '!');
+                    $filters[] = $not;
+                    continue;
+                }
+
+                if ($next === false) {
+                    // Nothing more to read
+                    break;
+                }
+
+                if ($next === ')') {
+                    if ($nestingLevel > 0) {
+                        break;
+                    }
+                    $this->parseError($next);
+                }
+                if ($next === '(') {
+                    $filters[] = $this->readFilters($nestingLevel + 1, null);
+                    continue;
+                }
+                if ($next === $op) {
+                    continue;
+                }
+                $this->parseError($next, "$op level $nestingLevel");
+
+            } else {
+                $filters[] = $filter;
+
+                if ($next === false) {
+                    // Got filter, nothing more to read
+                    break;
+                }
+
+                if ($op === '!') {
+                    $this->pos--;
+                    break;
+                }
+                if ($next === $op) {
+                    continue; // Break??
+                }
+
+                if ($next === ')') {
+                    if ($nestingLevel > 0) {
+                    echo "Got )<br>";
+                        break;
+                    }
+                    $this->parseError($next);
+                }
+                if ($op === null && in_array($next, array('&', '|'))) {
+                    $op = $next;
+                    continue;
+                }
+                $this->parseError($next);
+            }
+
+        }
+
+        if ($nestingLevel === 0 && count($filters) === 1) {
+            // There is only one filter expression, no chain
+            return $filters[0];
+        }
+        if ($op === null && count($filters) === 1) {
+            $op = '&';
+        }
+
+        switch ($op) {
+            case '&': return Filter::matchAll($filters);
+            case '|': return Filter::matchAny($filters);
+            case '!': return Filter::not($filters);
+            default: $this->parseError($op);
+        }
+    }
+
+    protected function parseQueryString($string)
+    {
+        $this->pos = 0;
+
+        $this->string = $string;
+
+        $this->length = strlen($string);
+        return $this->readFilters();
+    }
+
+    protected function readUnless($char)
+    {
+        $buffer = '';
+        while (false !== ($c = $this->readChar())) {
+            if (is_array($char)) {
+                if (in_array($c, $char)) {
+                    $this->pos--;
+                    break;
+                }
+            } else {
+                if ($c === $char) {
+                    $this->pos--;
+                    break;
+                }
+            }
+            $buffer .= $c;
+        }
+
+        return $buffer;
+    }
+
+    protected function readUnlessSpecialChar()
+    {
+        return $this->readUnless(array('=', '(', ')', '&', '|', '>', '<', '!'));
+    }
+
+    protected function readExpressionOperator()
+    {
+        return $this->readUnless(array('=', '>', '<', '!'));
+    }
+
+    protected function readChar()
+    {
+        if ($this->length > $this->pos) {
+            return $this->string[$this->pos++];
+        }
+        return false;
+    }
+
+    protected function nextChar()
+    {
+        if ($this->length > $this->pos) {
+            return $this->string[$this->pos];
+        }
+        return false;
+    }
+}