A new update for XOOPS (http://xoops.org) has  been released - XOOPS 2.5.1. According to the release article on XOOPS.org -

Several bugs have been fixed as well as security enhancement based on Aung Khant's report.

Please be aware that the bugfix is not complete and 2.5 series will be following small but frequent release rule so that users can take advantage of quick fixes.

There also have been some security reports about the XOOPS 2.5.x series, but the developers have assured the community they are properly addressed.

Driven by the efforts of the French XOOPS community, XOOPS has released a final version of 2.5.0. The improvements in version 2.5.0 are focused on the administration area, with a generous use of jQuery for a comfortable feel for common actions, similar to a desktop application.

There are no major compatibility issues between XOOPS 2.4.x and 2.5.0, but there have been some reports of issues in their forums, which is to be expected of any new release.

XOOPS 2.4.5 is a minor update to the XOOPS 2.4 platform, focusing on bugfixes and cosmetic changes to the underlying code.

There are detailed instructions to follow if you are using earlier versions of the xoopseditors - be sure to read and follow them. Please remember: If you're installing it over previous installation, make a BACKUP of your files and database first! Also note that some hacks done for previous XOOPS versions might not work with this release: testing before installing is always a good practice.

The XOOPS developers released 2 more upgrades to the 2.4.x series, moving quickly to a final release on both 2.4.3 and 2.4.4. They continue to patch bugs reported in the the 2.4.x series and some of the fixes include security updates. If are running an earlier version of 2.4, it is recommended you update to 2.4.4

In rapid succession, XOOPS has released 2.4.0, 2.4.1 and 2.4.2. Versions 2.4.1 and 2.4.2 are bug-fix releases of 2.4.0

 XOOPS 2.4.x series is the LAST version of XOOPS tested on and supporting PHP4. The next releases will be tested and certified exclusively on PHP5. It is also the last version series to support MySQL versions below 5.0.