Complex sentence: Pending changes is a review system which prevents certain edits from being publicly visible until they are approved by another editor; the system temporarily deployed on the English Wikipedia is a modified form of that in use on a number of other Wikimedia wikis.
Split into simpler sentences: Pending changes is a review system which prevents certain edits from being publicly visible until they are approved by another editor. The system temporarily deployed on the English Wikipedia is a modified form of that in use on a number of other Wikimedia wikis.