kochab

This plugin adds WordPress posts as topics in SimpleMachines Forum 1.1.7, and allows to put a link to this topic below the WordPress post for the user to add comments
More information on the plugin homepage: 
<a href="http://www.zonca.org/wordpress-post-to-smf" rel="nofollow ugc">WordPress plugin post to smf</a>
Main features:
<ul>
<li>SMF post is added when the WordPress post is published</li>
<li>SMF post is updated any time the WP post is updated</li>
<li>template function for linking from WP post to SMF post</li>
<li>link back from the SMF post to the WP post</li>
<li>it is possible to show on the SMF post just an excerpt </li>
</ul>
Admin page options:
<ul>
<li>SMF Board ID to post to </li>
<li>SMF User ID to set the post author</li>
<li>SMF Forum path and Url</li>
<li>Link from Forum to WordPress text</li>
<li>Max characters for SMF topic</li>
</ul>
If you use this plugin, please donate to support future improvements by clicking on the “Donate to this plugin” link

WordPress Post to SMF

This plugin adds Wordpress posts as topics in SimpleMachines Forum 1.1.7, and links the WP post to the comments in the forum

x0DSR

WP2SMFBridge is a simple one way bridge from WordPress to Simple Machine Forum (v2 tested). This means, this one uses databases of SMF Forum and sync to WP database every time a user performs login or logout action in WP. To get this working only use WP to register/login/logout. Also, WP and SMF must be installed in same domain, and should not be being accessed through a subdomain, though it still work. For example, if your website contains of WordPress for news and SMF for forum, if your news is mydomain.com, then your forums should be somewhere like mydomain.com/forum.
This plugin will do these following tasks:
<ul>
<li>If a user log in WP, then that user will be logged in SMF.</li>
<li>If a user logout in WP, then that user will be logout in SMF.</li>
<li>If a user created/register/change password in WP, those actions happen on SMF!</li>
<li>Users that are created in SMF can be used once disabled WP plugin.</li>
<li>For a full way integration use with SMF2WPBridge plugin. 
https://github.com/xchwarze/SMF2WPBridge 
http://custom.simplemachines.org/mods/index.php?mod=4030</li>
</ul>
<h3>Notes</h3>
Every time a user logged in SMF forum, same username (will be created if not exist) will be logged in WordPress. Because SMF is placed in higher order, so user in WordPress will be changed to SMF with same role.
For example, you have an administrator named “admin” in wordpress, after WP2SMFBridge fully activated, the SMF user named “admin” can login as that administrator. So be careful!

WP2SMFBridge

Login bridge from Wordpress to Simple Machine Forum.

WordPress Post to SMF vs WP2SMFBridge