Reason to use older versions of jQuery? [closed]

Question

I just read this question about how to fix something in jQuery 1.2.6 and don't understand why people would use older jQuery versions? What benefits/reasons are there?

To me I thought the answer was obviously to update to the newest jQuery, but there must be reasons why most of the responses don't say that.

EDIT: I understand being....say one version behind, especially when a new version just came out.. but being more than say... 3 versions behind? I don't see how the effort of making something work in the newer version would be more than making future things work with the older version.

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Thanks!

Answer 1

Newer versions often new ways of doing the same thing and infrequently but do break backward compatibility.

Sometimes, the sheer effort of regression testing (after upgrade) your site can be a deterrent.

Also, if there are other third party plugins that rely on a older version, then until they upgrade, you can't.