Movable Type 4 vs 5

I have a Movable Type site running MT 4.38, and I was wondering whether I should upgrade to 5.

For a while, MT 4 and 5 seemed to have been developed concurrently, but now I only see activity in MT 5. Has MT 4 been abandoned?

The person using the site is change averse, so I only want to upgrade if it's absolutely necessary (i.e. security issues).

Thanks

Solution

Yes. Movable Type 4.38 has a patch for a security vulnerability which you should be sure to apply. But beyond that, you should absolutely upgrade to Movable Type 5.2.3.

The big reason is that Movable Type 4.38 will be end-of-lifed on December 31, 2013. This means that there will be no security updates for Movable Type 4.38 after that date.

Movable Type 5 has a number of great new features that are huge improvements over MT 4.38:

New and improved Rich Text Editor based on TinyMCE
Revision history on the most-used objects in the CMS
List-management framework enhances Movable Type's ability to manage large amounts of data inside the CMS
Sortable categories and folders
Template tags for things like mt:EntryPrimaryCategory
Enhanced multi-blog support
Huge support improvements for Webkit-based browsers (Safari and Google Chrome) as well as IE 8 and 9
Login failure detection, allowing either account or IP address lock out

With all due respect, no one should be running a version of Movable Type that is no longer supported with security patches. It's foolish to think that any one person can know all of the possible security issues in an older version of a Content Management System such as Movable Type.