--- finediff.php.orig	2014-07-29 14:24:10.000000000 +0200
+++ finediff.php	2014-07-29 14:30:38.000000000 +0200
@@ -234,25 +234,25 @@
 
 	public function renderDiffToHTML() {
 		$in_offset = 0;
-		ob_start();
+		$html = '';
 		foreach ( $this->edits as $edit ) {
 			$n = $edit->getFromLen();
 			if ( $edit instanceof FineDiffCopyOp ) {
-				FineDiff::renderDiffToHTMLFromOpcode('c', $this->from_text, $in_offset, $n);
+				$html .= FineDiff::renderDiffToHTMLFromOpcode('c', $this->from_text, $in_offset, $n);
 				}
 			else if ( $edit instanceof FineDiffDeleteOp ) {
-				FineDiff::renderDiffToHTMLFromOpcode('d', $this->from_text, $in_offset, $n);
+				$html .= FineDiff::renderDiffToHTMLFromOpcode('d', $this->from_text, $in_offset, $n);
 				}
 			else if ( $edit instanceof FineDiffInsertOp ) {
-				FineDiff::renderDiffToHTMLFromOpcode('i', $edit->getText(), 0, $edit->getToLen());
+				$html .= FineDiff::renderDiffToHTMLFromOpcode('i', $edit->getText(), 0, $edit->getToLen());
 				}
 			else /* if ( $edit instanceof FineDiffReplaceOp ) */ {
-				FineDiff::renderDiffToHTMLFromOpcode('d', $this->from_text, $in_offset, $n);
-				FineDiff::renderDiffToHTMLFromOpcode('i', $edit->getText(), 0, $edit->getToLen());
+				$html .= FineDiff::renderDiffToHTMLFromOpcode('d', $this->from_text, $in_offset, $n);
+				$html .= FineDiff::renderDiffToHTMLFromOpcode('i', $edit->getText(), 0, $edit->getToLen());
 				}
 			$in_offset += $n;
 			}
-		return ob_get_clean();
+		return $html;
 		}
 
 	/**------------------------------------------------------------------------
@@ -277,18 +277,14 @@
 	* Re-create the "To" string from the "From" string and an "Opcodes" string
 	*/
 	public static function renderToTextFromOpcodes($from, $opcodes) {
-		ob_start();
-		FineDiff::renderFromOpcodes($from, $opcodes, array('FineDiff','renderToTextFromOpcode'));
-		return ob_get_clean();
+		return FineDiff::renderFromOpcodes($from, $opcodes, array('FineDiff','renderToTextFromOpcode'));
 		}
 
 	/**------------------------------------------------------------------------
 	* Render the diff to an HTML string
 	*/
 	public static function renderDiffToHTMLFromOpcodes($from, $opcodes) {
-		ob_start();
-		FineDiff::renderFromOpcodes($from, $opcodes, array('FineDiff','renderDiffToHTMLFromOpcode'));
-		return ob_get_clean();
+		return FineDiff::renderFromOpcodes($from, $opcodes, array('FineDiff','renderDiffToHTMLFromOpcode'));
 		}
 
 	/**------------------------------------------------------------------------
@@ -297,8 +293,9 @@
 	*/
 	public static function renderFromOpcodes($from, $opcodes, $callback) {
 		if ( !is_callable($callback) ) {
-			return;
+			return '';
 			}
+		$out = '';
 		$opcodes_len = strlen($opcodes);
 		$from_offset = $opcodes_offset = 0;
 		while ( $opcodes_offset <  $opcodes_len ) {
@@ -312,18 +309,19 @@
 				$n = 1;
 				}
 			if ( $opcode === 'c' ) { // copy n characters from source
-				call_user_func($callback, 'c', $from, $from_offset, $n, '');
+				$out .= call_user_func($callback, 'c', $from, $from_offset, $n, '');
 				$from_offset += $n;
 				}
 			else if ( $opcode === 'd' ) { // delete n characters from source
-				call_user_func($callback, 'd', $from, $from_offset, $n, '');
+				$out .= call_user_func($callback, 'd', $from, $from_offset, $n, '');
 				$from_offset += $n;
 				}
 			else /* if ( $opcode === 'i' ) */ { // insert n characters from opcodes
-				call_user_func($callback, 'i', $opcodes, $opcodes_offset + 1, $n);
+				$out .= call_user_func($callback, 'i', $opcodes, $opcodes_offset + 1, $n);
 				$opcodes_offset += 1 + $n;
 				}
 			}
+		return $out;
 		}
 
 	/**
@@ -665,24 +663,26 @@
 	*/
 	private static function renderToTextFromOpcode($opcode, $from, $from_offset, $from_len) {
 		if ( $opcode === 'c' || $opcode === 'i' ) {
-			echo substr($from, $from_offset, $from_len);
+			return substr($from, $from_offset, $from_len);
 			}
+		return '';
 		}
 
 	private static function renderDiffToHTMLFromOpcode($opcode, $from, $from_offset, $from_len) {
 		if ( $opcode === 'c' ) {
-			echo htmlentities(substr($from, $from_offset, $from_len));
+			return htmlentities(substr($from, $from_offset, $from_len));
 			}
 		else if ( $opcode === 'd' ) {
 			$deletion = substr($from, $from_offset, $from_len);
 			if ( strcspn($deletion, " \n\r") === 0 ) {
 				$deletion = str_replace(array("\n","\r"), array('\n','\r'), $deletion);
 				}
-			echo '<del>', htmlentities($deletion), '</del>';
+			return '<del>' . htmlentities($deletion) . '</del>';
 			}
 		else /* if ( $opcode === 'i' ) */ {
- 			echo '<ins>', htmlentities(substr($from, $from_offset, $from_len)), '</ins>';
+ 			return '<ins>' . htmlentities(substr($from, $from_offset, $from_len)) . '</ins>';
 			}
+		return '';
 		}
 	}