Index: reference/template-changelog.php
===================================================================
--- reference/template-changelog.php	(revision 3648)
+++ reference/template-changelog.php	(working copy)
@@ -14,19 +14,35 @@
 	<hr/>
 	<section class="changelog">
 		<h3><?php _e( 'Changelog', 'wporg' ); ?></h3>
-		<ul>
-			<?php foreach ( $changelog_data as $version => $data ) : ?>
-				<li>
-					<strong><?php _e( 'Since:', 'wporg' ); ?></strong>
-					<?php printf(
-					/* translators: %s: WordPress version */
-						__( 'WordPress %s', 'wporg' ),
-						sprintf( '<a href="%1$s">%2$s</a>', esc_url( $data['since_url'] ), esc_html( $version ) )
-					); ?>
-					<?php echo $data['description']; // escaped in get_changelog_data() ?>
-				</li>
-			<?php endforeach; ?>
-		</ul>
+
+		<table>
+			<caption class="screen-reader-text"><?php _e( 'Changelog', 'wporg' ); ?></caption>
+			<thead>
+				<tr>
+					<th><?php _e( 'Version', 'wporg' ); ?></th>
+					<th><?php _e( 'Description', 'wporg' ); ?></th>
+				</tr>
+			</thead>
+
+			<tbody>
+				<?php $count = 0; ?>
+				<?php foreach ( $changelog_data as $version => $data ) : ?>
+					<?php
+					$data['description'] = ( 1 === ++$count ) ? __( 'Introduced.', 'wporg' ) : $data['description'];
+
+					$version_link = sprintf( '<a href="%1$s">%2$s</a>',
+						esc_url( $data['since_url'] ),
+						esc_html( $version )
+					);
+					?>
+
+					<tr>
+						<td><?php echo $version_link; ?></td>
+						<td><?php echo $data['description']; ?></td>
+					</tr>
+				<?php endforeach; ?>
+			</tbody>
+		</table>
 	</section>
 <?php endif; ?>