diff --git a/README.md b/README.md
index e6acb85..46cc3a0 100644
--- a/README.md
+++ b/README.md
@@ -38,6 +38,7 @@ Installing
       - Ensure your web host is running Linux.
       - Install [mediainfo](http://mediaarea.net/en/MediaInfo) and [ffmpegthumbnailer](https://code.google.com/p/ffmpegthumbnailer/).  On Ubuntu, run ``sudo apt-get install mediainfo ffmpegthumbnailer``.
       - Set ``TINYIB_WEBM`` to ``true``.
+    - When setting ``TINYIB_DBMODE`` to ``pdo``, note that PDO mode has been tested on **MySQL databases only**.  Theoretically it will work with any applicable driver, but this is not guaranteed.  If you use an alternative driver, please report back regarding how it works.
  6. [CHMOD](http://en.wikipedia.org/wiki/Chmod) write permissions to these directories:
     - ./ (the directory containing TinyIB)
     - ./src/
diff --git a/imgboard.php b/imgboard.php
index 6572077..0f80b77 100644
--- a/imgboard.php
+++ b/imgboard.php
@@ -42,7 +42,7 @@ foreach ($writedirs as $dir) {
 }
 
 $includes = array("inc/defines.php", "inc/functions.php", "inc/html.php");
-if (in_array(TINYIB_DBMODE, array('flatfile', 'mysql', 'mysqli', 'sqlite'))) {
+if (in_array(TINYIB_DBMODE, array('flatfile', 'mysql', 'mysqli', 'sqlite', 'pdo'))) {
 	$includes[] = 'inc/database_' . TINYIB_DBMODE . '.php';
 } else {
 	fancyDie("Unknown database mode specificed");
diff --git a/inc/database_pdo.php b/inc/database_pdo.php
new file mode 100644
index 0000000..5af52db
--- /dev/null
+++ b/inc/database_pdo.php
@@ -0,0 +1,207 @@
+<?php
+if (!defined('TINYIB_BOARD')) {
+	die('');
+}
+
+if (TINYIB_DBDSN == '') { // Build a default (likely MySQL) DSN
+	$dsn = TINYIB_DBDRIVER . ":host=" . TINYIB_DBHOST;
+	if (TINYIB_DBPORT > 0) {
+		$dsn .= ";port=" . TINYIB_DBPORT;
+	}
+	$dsn .= ";dbname=" . TINYIB_DBNAME;
+} else { // Use a custom DSN
+	$dsn = TINYIB_DBDSN;
+}
+
+$options = array(PDO::ATTR_PERSISTENT => true,
+	PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
+	PDO::MYSQL_ATTR_INIT_COMMAND => 'SET NAMES utf8');
+
+try {
+	$dbh = new PDO($dsn, TINYIB_DBUSERNAME, TINYIB_DBPASSWORD, $options);
+} catch (PDOException $e) {
+	fancyDie("Failed to connect to the database: " . $e->getMessage());
+}
+
+// Create the posts table if it does not exist
+$dbh->query("SHOW TABLES LIKE " . $dbh->quote(TINYIB_DBPOSTS));
+if ($dbh->query("SELECT FOUND_ROWS()")->fetchColumn() == 0) {
+	$dbh->exec($posts_sql);
+}
+
+// Create the bans table if it does not exist
+$dbh->query("SHOW TABLES LIKE " . $dbh->quote(TINYIB_DBBANS));
+if ($dbh->query("SELECT FOUND_ROWS()")->fetchColumn() == 0) {
+	$dbh->exec($bans_sql);
+}
+
+# Utililty
+function pdoQuery($sql, $params = false) {
+	global $dbh;
+
+	if ($params) {
+		$statement = $dbh->prepare($sql);
+		$statement->execute($params);
+	} else {
+		$statement = $dbh->query($sql);
+	}
+
+	return $statement;
+}
+
+# Post Functions
+function uniquePosts() {
+	$result = pdoQuery("SELECT COUNT(DISTINCT(ip)) FROM " . TINYIB_DBPOSTS);
+	return (int)$result->fetchColumn();
+}
+
+function postByID($id) {
+	$result = pdoQuery("SELECT * FROM " . TINYIB_DBPOSTS . " WHERE id = ?", array($id));
+	if ($result) {
+		return $result->fetch();
+	}
+}
+
+function threadExistsByID($id) {
+	$result = pdoQuery("SELECT COUNT(*) FROM " . TINYIB_DBPOSTS . " WHERE id = ? AND parent = 0", array($id));
+	return $result->fetchColumn() != 0;
+}
+
+function insertPost($post) {
+	global $dbh;
+	$now = time();
+	$stm = $dbh->prepare("INSERT INTO " . TINYIB_DBPOSTS . " (parent, timestamp, bumped, ip, name, tripcode, email,   nameblock, subject, message, password,   file, file_hex, file_original, file_size, file_size_formatted, image_width, image_height, thumb, thumb_width, thumb_height) " .
+		" VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)");
+	$stm->execute(array($post['parent'], $now, $now, $_SERVER['REMOTE_ADDR'], $post['name'], $post['tripcode'], $post['email'],
+		$post['nameblock'], $post['subject'], $post['message'], $post['password'],
+		$post['file'], $post['file_hex'], $post['file_original'], $post['file_size'], $post['file_size_formatted'],
+		$post['image_width'], $post['image_height'], $post['thumb'], $post['thumb_width'], $post['thumb_height']));
+	return $dbh->lastInsertId();
+}
+
+function bumpThreadByID($id) {
+	$now = time();
+	pdoQuery("UPDATE " . TINYIB_DBPOSTS . " SET bumped = ? WHERE id = ?", array($now, $id));
+}
+
+function countThreads() {
+	$result = pdoQuery("SELECT COUNT(*) FROM " . TINYIB_DBPOSTS . " WHERE parent = 0");
+	return (int)$result->fetchColumn();
+}
+
+function allThreads() {
+	$threads = array();
+	$results = pdoQuery("SELECT * FROM " . TINYIB_DBPOSTS . " WHERE parent = 0 ORDER BY bumped DESC");
+	while ($row = $results->fetch()) {
+		$threads[] = $row;
+	}
+	return $threads;
+}
+
+function numRepliesToThreadByID($id) {
+	$result = pdoQuery("SELECT COUNT(*) FROM " . TINYIB_DBPOSTS . " WHERE parent = ?", array($id));
+	return (int)$result->fetchColumn();
+}
+
+function postsInThreadByID($id) {
+	$posts = array();
+	$results = pdoQuery("SELECT * FROM " . TINYIB_DBPOSTS . " WHERE id = ? OR parent = ? ORDER BY id ASC", array($id, $id));
+	while ($row = $results->fetch(PDO::FETCH_ASSOC)) {
+		$posts[] = $row;
+	}
+	return $posts;
+}
+
+function postsByHex($hex) {
+	$posts = array();
+	$results = pdoQuery("SELECT * FROM " . TINYIB_DBPOSTS . " WHERE file_hex = ? LIMIT 1", array($hex));
+	while ($row = $results->fetch(PDO::FETCH_ASSOC)) {
+		$posts[] = $row;
+	}
+	return $posts;
+}
+
+function latestPosts() {
+	$posts = array();
+	$results = pdoQuery("SELECT * FROM " . TINYIB_DBPOSTS . " ORDER BY timestamp DESC LIMIT 10");
+	while ($row = $results->fetch(PDO::FETCH_ASSOC)) {
+		$posts[] = $row;
+	}
+	return $posts;
+}
+
+function deletePostByID($id) {
+	$posts = postsInThreadByID($id);
+	foreach ($posts as $post) {
+		if ($post['id'] != $id) {
+			deletePostImages($post);
+			pdoQuery("DELETE FROM " . TINYIB_DBPOSTS . " WHERE id = ?", array($id));
+		} else {
+			$thispost = $post;
+		}
+	}
+	if (isset($thispost)) {
+		if ($thispost['parent'] == TINYIB_NEWTHREAD) {
+			@unlink('res/' . $thispost['id'] . '.html');
+		}
+		deletePostImages($thispost);
+		pdoQuery("DELETE FROM " . TINYIB_DBPOSTS . " WHERE id = ?", array($thispost['id']));
+	}
+}
+
+function trimThreads() {
+	$limit = (int)TINYIB_MAXTHREADS;
+	if ($limit > 0) {
+		$results = pdoQuery("SELECT id FROM " . TINYIB_DBPOSTS . " WHERE parent = 0 ORDER BY bumped LIMIT 100 OFFSET " . $limit
+		);
+		# old mysql, sqlite3: SELECT id FROM $table ORDER BY bumped LIMIT $limit,100
+		# mysql, postgresql, sqlite3: SELECT id FROM $table ORDER BY bumped LIMIT 100 OFFSET $limit
+		# oracle: SELECT id FROM ( SELECT id, rownum FROM $table ORDER BY bumped) WHERE rownum >= $limit
+		# MSSQL: WITH ts AS (SELECT ROWNUMBER() OVER (ORDER BY bumped) AS 'rownum', * FROM $table) SELECT id FROM ts WHERE rownum >= $limit
+		foreach ($results as $post) {
+			deletePostByID($post['id']);
+		}
+	}
+}
+
+function lastPostByIP() {
+	$result = pdoQuery("SELECT * FROM " . TINYIB_DBPOSTS . " WHERE ip = ? ORDER BY id DESC LIMIT 1", array($_SERVER['REMOTE_ADDR']));
+	return $result->fetch(PDO::FETCH_ASSOC);
+}
+
+# Ban Functions
+function banByID($id) {
+	$result = pdoQuery("SELECT * FROM " . TINYIB_DBBANS . " WHERE id = ?", array($id));
+	return $result->fetch(PDO::FETCH_ASSOC);
+}
+
+function banByIP($ip) {
+	$result = pdoQuery("SELECT * FROM " . TINYIB_DBBANS . " WHERE ip = ? LIMIT 1", array($ip));
+	return $result->fetch(PDO::FETCH_ASSOC);
+}
+
+function allBans() {
+	$bans = array();
+	$results = pdoQuery("SELECT * FROM " . TINYIB_DBBANS . " ORDER BY timestamp DESC");
+	while ($row = $results->fetch(PDO::FETCH_ASSOC)) {
+		$bans[] = $row;
+	}
+	return $bans;
+}
+
+function insertBan($ban) {
+	global $dbh;
+	$now = time();
+	$stm = $dbh->prepare("INSERT INTO " . TINYIB_DBBANS . " (ip, timestamp, expire, reason) VALUES (?, ?, ?, ?)");
+	$stm->execute(array($ban['ip'], $now, $ban['expire'], $ban['reason']));
+	return $dbh->lastInsertId();
+}
+
+function clearExpiredBans() {
+	$now = time();
+	pdoQuery("DELETE FROM " . TINYIB_DBBANS . " WHERE expire > 0 AND expire <= ?", array($now));
+}
+
+function deleteBanByID($id) {
+	pdoQuery("DELETE FROM " . TINYIB_DBBANS . " WHERE id = ?", array($id));
+}
diff --git a/inc/defines.php b/inc/defines.php
index 7af2f49..1807cfd 100644
--- a/inc/defines.php
+++ b/inc/defines.php
@@ -30,3 +30,12 @@ if (!defined('TINYIB_WEBM')) {
 if (!defined('TINYIB_DBMIGRATE')) {
 	define('TINYIB_DBMIGRATE', false);
 }
+if (!defined('TINYIB_DBPORT')) {
+	define('TINYIB_DBPORT', 3306);
+}
+if (!defined('TINYIB_DBDRIVER')) {
+	define('TINYIB_DBDRIVER', 'pdo');
+}
+if (!defined('TINYIB_DBDSN')) {
+	define('TINYIB_DBDSN', '');
+}
diff --git a/inc/functions.php b/inc/functions.php
index 27b0f97..7882b73 100644
--- a/inc/functions.php
+++ b/inc/functions.php
@@ -29,7 +29,7 @@ $posts_sql = "CREATE TABLE `" . TINYIB_DBPOSTS . "` (
 	PRIMARY KEY	(`id`),
 	KEY `parent` (`parent`),
 	KEY `bumped` (`bumped`)
-) ENGINE=MyISAM";
+)";
 
 $bans_sql = "CREATE TABLE `" . TINYIB_DBBANS . "` (
 	`id` mediumint(7) unsigned NOT NULL auto_increment,
@@ -39,7 +39,7 @@ $bans_sql = "CREATE TABLE `" . TINYIB_DBBANS . "` (
 	`reason` text NOT NULL,
 	PRIMARY KEY	(`id`),
 	KEY `ip` (`ip`)
-) ENGINE=MyISAM";
+)";
 
 function cleanString($string) {
 	$search = array("<", ">");
diff --git a/inc/html.php b/inc/html.php
index 309daa6..60c7a37 100644
--- a/inc/html.php
+++ b/inc/html.php
@@ -18,7 +18,7 @@ EOF;
 		<link rel="alternate stylesheet" type="text/css" href="css/burichan.css" title="Burichan">
 		<meta http-equiv="content-type" content="text/html;charset=UTF-8">
 		<meta http-equiv="pragma" content="no-cache">
-		<meta http-equiv="expires" content="-1">
+		<meta http-equiv="expires" content="0">
 	</head>
 EOF;
 	return $return;
diff --git a/settings.default.php b/settings.default.php
index ac9c5ed..6fc6d14 100644
--- a/settings.default.php
+++ b/settings.default.php
@@ -20,13 +20,19 @@ define('TINYIB_LOGO', ""); // Logo HTML
 define('TINYIB_TRIPSEED', ""); // Enter some random text - Used when generating secure tripcodes - Must not change once set
 define('TINYIB_ADMINPASS', ""); // Text entered at the manage prompt to gain administrator access
 define('TINYIB_MODPASS', ""); // Moderators only have access to delete posts  ["" to disable]
-define('TINYIB_DBMODE', "flatfile"); // Choose: flatfile / mysql / mysqli / sqlite  (flatfile is not recommended for popular sites)
+define('TINYIB_DBMODE', "flatfile"); // Choose: flatfile / mysql / mysqli / sqlite / pdo  (flatfile is not recommended for popular sites)
 define('TINYIB_DBMIGRATE', false); // Enable database migration tool  (see README for instructions)
 
-// Note: The following only apply when TINYIB_DBMODE is set to mysql or mysqli (recommended)
+// Note: The following only apply when TINYIB_DBMODE is set to mysql, mysqli (recommended over mysql) or pdo with default (blank) TINYIB_DBDSN (this is recommended most)
 define('TINYIB_DBHOST', "localhost");
+define('TINYIB_DBPORT', 3306); // Set to 0 if you are using a UNIX socket as the host
 define('TINYIB_DBUSERNAME', "");
 define('TINYIB_DBPASSWORD', "");
 define('TINYIB_DBNAME', "");
 define('TINYIB_DBPOSTS', TINYIB_BOARD . "_posts");
 define('TINYIB_DBBANS', "bans");
+
+// Note: The following only apply when TINYIB_DBMODE is set to pdo  (see README for instructions)
+define('TINYIB_DBDRIVER', "mysql"); // PDO driver to use (mysql / sqlite / pgsql / etc.)
+define('TINYIB_DBDSN', ""); // Enter a custom DSN to override all of the connection/driver settings above  (see README for instructions)
+# You should still set TINYIB_DBDRIVER appropriately when using a custom DSN