Maintaining multiple versions of a collection of content items

A system comprising:

• one or more processors;
• and
• a computer-readable storage medium having processor-executable instructions stored therein for causing the one or more processors to:
• maintain, at a content management system, a first version of a collection of content items and a second version of the collection of content items, the first version of the collection of content items and the second version of the collection of content items being accessible to a first group of users, the second version of the collection of content items being accessible to a second group of users, and the first group of users being a subset of the second group of users;
• receive first information associated with a first change to at least one item of the first version of the collection of content items
• store the first change in a change history associated with the first version of a collection of content items, the change history comprises a set of changes associated with the first version of the collection of content items;
• apply the first change to the first version of the collection of content items accessible to the first group of users, the first change to the first version of the collection of content items being displayed as a marked version of the collection of content items, wherein the second version of the collection of content items does not include the first change;
• receive an acceptance message instructing the content management system to apply the first change to the second version of the collection of content items;
• and
• based on the acceptance message, apply synchronize the first change applied to the first version of the collection of content items to the second version of the collection of content items.

A non-transitory computer-readable medium including one or more sequences of instructions which, when executed by one or more processors, cause:

• maintaining a first version of a collection of content items and a second version of the collection of content items, the first version of the collection of content items and the second version of the collection of content items being accessible to a first group of users, the second version of the collection of content items being accessible to a second group of users, and the first group of users being a subset of the second group of users;
• receiving first information associated with a first change to the first version of the collection of content items;
• storing, by the content management system, the first change in a change history associated with the first version of a collection of content items, the change history comprises a set of changes associated with the first version of the collection of content items;
• applying the first change to the first version of the collection of content items accessible to the first group of users, the first change to the first version of the collection of content items being displayed as a marked version of the collection of content items, wherein the second version of the collection of content items does not include the first change;
• receiving, by the content management system, an acceptance message instructing the content management system to apply the first change to the second version of the collection of content items;
• and
• upon receiving the acceptance message, applying, by the content management system, the first change to the second version of the collection of content items.