Today we release MooTools Core 1.4.4 which is a critical maintenance release. 1.4.3 release introduced a bug as a result of fixing another bug. Specifically, 1.4.3 did not allow custom attributes (e.g. data- or non-standard attributes). See this issue for a full explanation and solution.

We recommend that all users upgrade to 1.4.4 as soon as possible.

Today we release MooTools Core 1.4.3 which is a small maintenance release. Upgrading from 1.4.2 should not cause any backward incompatibilities. We recommend that all users upgrade to 1.4.3 as soon as possible.