The latest release J!WHMCS Integrator, version 2.6, offers a tremendous improvement over previous versions. Some of the feature highlights in version 2.6 include:

Sync Manager (new in v2.6) to provide means to add WHMCS users into Joomla
Simplification of the installation and configuration of the product
Performance has been improved by removing redundant API calls
Bridging of USERNAMES to WHMCS and vice versa
Inclusion of the Dunamis Library for Joomla!
Search WHMCS knowledgebase articles from within the Joomla Search function
Be sure to check upgrade and installation instructions prior to install.

Note also that support for Joomla! 1.5 has been officially dropped with the release of J!WHMCS Integrator version 2.5.

Complete Visual Integration
With J!WHMCS Integrator, your WHMCS clients and Joomla users are bridged allowing you to customize your client's experience on your site. Your clients can log in anywhere on your site and be logged into both WHMCS and Joomla. Clients can change their profile in WHMCS and any updates are carried over to Joomla and vice versa.

User Account Bridging
Your WHMCS clients and Joomla users are bridged with J!WHMCS Integrator, allowing you to customize your client's experience on your site. Your clients can log in anywhere on your site and be logged into both WHMCS and Joomla. Clients can change their profile in WHMCS and those updates are carried over to Joomla.

Username or Email Address
Your WHMCS clients and Joomla users are bridged with J!WHMCS Integrator, allowing you to customize your client's experience on your site. Your clients can log in anywhere on your site and be logged into both WHMCS and Joomla. Clients can change their profile in WHMCS and those updates are carried over to Joomla.

Sub-Account Utilization
Provide options for your corporate clients with sub-account integration. Sub-accounts permit your clients to use sub-account within their WHMCS profile and can be bridged to actual Joomla accounts. J!WHMCS Integrator permits a sub-account user to log in through Joomla or WHMCS and bridge them over to a Joomla account.

Integration In Your Language!
Both Joomla! and WHMCS are capable of multi-lingual usage; with J!WHMCS Integrator, now you can display an integrated Joomla site in languages supported by your WHMCS application! Right to left? No problem! J!WHMCS Integrator supports the use of Joomfish in Joomla 1.5 or the use of the native language capabilities found in Joomla 2.5.

Notes
J!WHMCS Integrator 2.6 is no longer backwards compatible with WHMCS version 5.2 or earlier.
J!WHMCS Integrator 2.6 does NOT support Joomla! 1.5 any longer.
J!WHMCS Integrator requires the installation of the WHMCS Addon Module

.