diff --git a/composer.json b/composer.json
index a2447af3..52214935 100644
--- a/composer.json
+++ b/composer.json
@@ -1,5 +1,5 @@
 {
-    "name": "leafo/lessphp",
+    "name": "tocsick/lessphp",
     "type": "library",
     "description": "lessphp is a compiler for LESS written in PHP.",
     "homepage": "http://leafo.net/lessphp/",
diff --git a/lessc.inc.php b/lessc.inc.php
index 2292f219..bc64c10f 100644
--- a/lessc.inc.php
+++ b/lessc.inc.php
@@ -51,6 +51,12 @@ class lessc {
 	public $mPrefix = '$'; // prefix of abstract blocks
 	public $parentSelector = '&';
 
+	static public $lengths = array( "px", "m", "cm", "mm", "in", "pt", "pc" );
+	static public $times = array( "s", "ms" );
+	static public $angles = array( "rad", "deg", "grad", "turn" );
+	
+	static public $lengths_to_base = array( 1, 3779.52755906, 37.79527559, 3.77952756, 96, 1.33333333, 16  );
+	
 	public $importDisabled = false;
 	public $importDir = '';
 
@@ -885,7 +891,7 @@ public function compileValue($value) {
 
 	protected function lib_pow($args) {
 		list($base, $exp) = $this->assertArgs($args, 2, "pow");
-		return pow($this->assertNumber($base), $this->assertNumber($exp));
+		return array( "number", pow($this->assertNumber($base), $this->assertNumber($exp)), $args[2][0][2] );
 	}
 
 	protected function lib_pi() {
@@ -894,9 +900,67 @@ protected function lib_pi() {
 
 	protected function lib_mod($args) {
 		list($a, $b) = $this->assertArgs($args, 2, "mod");
-		return $this->assertNumber($a) % $this->assertNumber($b);
+		return array( "number", $this->assertNumber($a) % $this->assertNumber($b), $args[2][0][2] );
+	}
+
+	protected function lib_convert($args) {
+		list($value, $to) = $this->assertArgs($args, 2, "convert");
+		
+		// If it's a keyword, grab the string version instead
+		if( is_array( $to ) && $to[0] == "keyword" )
+			$to = $to[1];
+		
+		return $this->convert( $value, $to );
+	}
+	
+	protected function lib_abs($num) {
+		return array( "number", abs($this->assertNumber($num)), $num[2] );
+	}
+	
+	protected function lib_min($args) {
+		$values = $this->assertMinArgs($args, 1, "min");
+		
+		$first_format = $values[0][2];
+		
+		$min_index = 0;
+		$min_value = $values[0][1];
+		
+		for( $a = 0; $a < sizeof( $values ); $a++ )
+		{
+			$converted = $this->convert( $values[$a], $first_format );
+			
+			if( $converted[1] < $min_value )
+			{
+				$min_index = $a;
+				$min_value = $values[$a][1];
+			}
+		}
+		
+		return $values[ $min_index ];
+	}
+	
+	protected function lib_max($args) {
+		$values = $this->assertMinArgs($args, 1, "max");
+		
+		$first_format = $values[0][2];
+		
+		$max_index = 0;
+		$max_value = $values[0][1];
+		
+		for( $a = 0; $a < sizeof( $values ); $a++ )
+		{
+			$converted = $this->convert( $values[$a], $first_format );
+			
+			if( $converted[1] > $max_value )
+			{
+				$max_index = $a;
+				$max_value = $values[$a][1];
+			}
+		}
+		
+		return $values[ $max_index ];
 	}
-
+	
 	protected function lib_tan($num) {
 		return tan($this->assertNumber($num));
 	}
@@ -1306,6 +1370,21 @@ public function assertArgs($value, $expectedArgs, $name="") {
 			return $values;
 		}
 	}
+	
+	public function assertMinArgs($value, $expectedMinArgs, $name="") {
+		if ($value[0] !== "list" || $value[1] != ",") $this->throwError("expecting list");
+		$values = $value[2];
+		$numValues = count($values);
+		if ($expectedMinArgs > $numValues) {
+			if ($name) {
+				$name = $name . ": ";
+			}
+	
+			$this->throwError("${name}expecting at least $expectedMinArgs arguments, got $numValues");
+		}
+	
+		return $values;
+	}
 
 	protected function toHSL($color) {
 		if ($color[0] == 'hsl') return $color;
@@ -1674,7 +1753,79 @@ protected function stringConcatenate($left, $right) {
 			return $strRight;
 		}
 	}
-
+	
+	protected function convert( $number, $to )
+	{
+		$value = $this->assertNumber( $number );
+		$from = $number[2];
+		
+		// easy out
+		if( $from == $to )
+			return $number;
+
+		// check if the from value is a length
+		if( ( $from_index = array_search( $from, self::$lengths ) ) !== false ) {
+			// make sure to value is too
+			if( in_array( $to, self::$lengths ) ) {
+				// do the actual conversion
+				$to_index = array_search( $to, self::$lengths );
+				$px = $value * self::$lengths_to_base[ $from_index ];
+				$result = $px * ( 1 / self::$lengths_to_base[ $to_index ] );
+				
+				$result = round( $result, 8 );
+				return array( "number", $result, $to );
+			}
+		}
+		
+		// do the same check for times
+		if( in_array( $from, self::$times ) ) {
+			if( in_array( $to, self::$times ) ) {
+				// currently only ms and s are valid
+				if( $to == "ms" )
+					$result = $value * 1000;
+				else
+					$result = $value / 1000;
+					
+				$result = round( $result, 8 );
+				return array( "number", $result, $to );
+			}
+		}
+		
+		// lastly check for an angle
+		if( in_array( $from, self::$angles ) ) {
+			// convert whatever angle it is into degrees
+			if( $from == "rad" )
+				$deg = rad2deg( $value );
+			
+			else if( $from == "turn" )
+				$deg = $value * 360;
+			
+			else if( $from == "grad" )
+				$deg = $value / (400 / 360);
+			
+			else
+				$deg = $value;
+
+			// Then convert it from degrees into desired unit
+			if( $to == "deg" )
+				$result = $deg;
+
+			if( $to == "rad" )
+				$result = deg2rad( $deg );
+			
+			if( $to == "turn" )
+				$result = $value / 360;
+			
+			if( $to == "grad" )
+				$result = $value * (400 / 360);
+			
+			$result = round( $result, 8 );
+			return array( "number", $result, $to );
+		}
+		
+		// we don't know how to convert these
+		$this->throwError( "Cannot convert {$from} to {$to}" );
+	}
 
 	// make sure a color's components don't go out of bounds
 	protected function fixColor($c) {
diff --git a/tests/ErrorHandlingTest.php b/tests/ErrorHandlingTest.php
index de02f065..2adb0d51 100644
--- a/tests/ErrorHandlingTest.php
+++ b/tests/ErrorHandlingTest.php
@@ -78,4 +78,44 @@ public function testGuardUnmatchedType() {
 			'.selector { .colors-only("string value"); }'
 		);
 	}
+	
+	/**
+	 * @expectedException		Exception
+	 * @expectedExceptionMessage	expecting at least 1 arguments, got 0
+	 */
+	public function testMinNoArguments() {
+		$this->compile(
+				'.selector{ min: min(); }'
+		);
+	}
+	
+	/**
+	 * @expectedException		Exception
+	 * @expectedExceptionMessage	expecting at least 1 arguments, got 0
+	 */
+	public function testMaxNoArguments() {
+		$this->compile(
+				'.selector{ max: max(); }'
+		);
+	}
+	
+	/**
+	 * @expectedException		Exception
+	 * @expectedExceptionMessage	Cannot convert % to px
+	 */
+	public function testMaxIncompatibleTypes() {
+		$this->compile(
+				'.selector{ max: max( 10px, 5% ); }'
+		);
+	}
+	
+	/**
+	 * @expectedException		Exception
+	 * @expectedExceptionMessage	Cannot convert px to s
+	 */
+	public function testConvertIncompatibleTypes() {
+		$this->compile(
+				'.selector{ convert: convert( 10px, s ); }'
+		);
+	}
 }
diff --git a/tests/InputTest.php b/tests/InputTest.php
index 32db95bc..c0ce1ce0 100644
--- a/tests/InputTest.php
+++ b/tests/InputTest.php
@@ -44,7 +44,7 @@ public function testInputFile($inFname) {
 
 		$input = file_get_contents($inFname);
 		$output = file_get_contents($outFname);
-
+				
 		$this->assertEquals($output, $this->less->parse($input));
 	}
 
diff --git a/tests/inputs/builtins.less b/tests/inputs/builtins.less
index f9301e04..661335a2 100644
--- a/tests/inputs/builtins.less
+++ b/tests/inputs/builtins.less
@@ -72,8 +72,22 @@ format {
 
 	pow: pow(2,4);
 	pi: pi();
-	mod: mod(14,10);
-
+	mod1: mod(14,10);
+	mod2: mod(14px,10);
+	
+	abs1: abs(-5px);
+	abs2: abs(5%);
+	abs3: abs(-10);
+	
+	min1: min(2px,5px,10px);
+	min2: min(5,1,8);
+	
+	max1: max(2%,20%,5%);
+	max2: max(5,4,10);
+	
+	max-convert: max(1px,1cm);
+	min-convert: min(1px,1cm);
+	
 	tan: tan(1);
 	cos: cos(1);
 	sin: sin(1);
@@ -85,6 +99,27 @@ format {
 	sqrt: sqrt(8);
 }
 
+#convert {
+	px2cm: convert(1px,cm);
+	px2mm: convert(1px,mm);
+	px2in: convert(1px,in);
+	px2pt: convert(1px,pt);
+	px2pc: convert(1px,pc);
+	
+	cm2px: convert(1cm,px);
+	in2px: convert(1in,px);
+	cm2in: convert(1cm,in);
+	
+	s2ms: convert(1s,ms);
+	ms2s: convert(1ms,s);
+	
+	deg2rad: convert(1deg,rad);
+	rad2deg: convert(1rad,deg);
+	deg2turn: convert(1deg,turn);
+	turn2deg: convert(1turn,deg);
+	deg2grad: convert(1deg,grad);
+	grad2deg: convert(1grad,deg);
+}
 
 #unit {
 	@unit: "em";
diff --git a/tests/outputs/builtins.css b/tests/outputs/builtins.css
index 6ac21f2c..95bad4d0 100644
--- a/tests/outputs/builtins.css
+++ b/tests/outputs/builtins.css
@@ -44,7 +44,17 @@ format {
   ex4: 2;
   pow: 16;
   pi: 3.1415926535898;
-  mod: 4;
+  mod1: 4;
+  mod2: 4px;
+  abs1: 5px;
+  abs2: 5%;
+  abs3: 10;
+  min1: 2px;
+  min2: 1;
+  max1: 20%;
+  max2: 10;
+  max-convert: 1cm;
+  min-convert: 1px;
   tan: 1.5574077246549;
   cos: 0.54030230586814;
   sin: 0.8414709848079;
@@ -53,6 +63,24 @@ format {
   asin: 1.5707963267949rad;
   sqrt: 2.8284271247462;
 }
+#convert {
+  px2cm: 0.02645833cm;
+  px2mm: 0.26458333mm;
+  px2in: 0.01041667in;
+  px2pt: 0.75pt;
+  px2pc: 0.0625pc;
+  cm2px: 37.79527559px;
+  in2px: 96px;
+  cm2in: 0.39370079in;
+  s2ms: 1000ms;
+  ms2s: 0.001s;
+  deg2rad: 0.01745329rad;
+  rad2deg: 57.29577951deg;
+  deg2turn: 0.00277778turn;
+  turn2deg: 360deg;
+  deg2grad: 1.11111111grad;
+  grad2deg: 0.9deg;
+}
 #unit {
   unit-lit: 10;
   unit-arg: 10s;