14. A system comprising: a hardware processor; and a storage device communicatively coupled with the hardware processor, the storage device storing instructions that cause the hardware processor to perform operations comprising: receiving, from a reviewer, multiple comments about a word processing document; presenting the multiple comments to an editor; for each comment of the multiple comments presented to the editor, receiving, from the editor, an instruction to access the comment, accessing the comment in response to the instruction, receiving, from the editor, one or more changes to the word processing document that address the accessed comment, and storing the one or more received changes to the word processing document in a document difference record associated with the accessed comment; receiving, from the reviewer, a request selecting a first comment from among the multiple accessed comments; and presenting, to the reviewer in response to the request, the word processing document and a first document difference record associated with the selected first comment, while hiding document difference records that correspond to unselected comments from among the multiple comments.
14. A system comprising: a hardware processor; and a storage device communicatively coupled with the hardware processor, the storage device storing instructions that cause the hardware processor to perform operations comprising: receiving, from a reviewer, multiple comments about a word processing document; presenting the multiple comments to an editor; for each comment of the multiple comments presented to the editor, receiving, from the editor, an instruction to access the comment, accessing the comment in response to the instruction, receiving, from the editor, one or more changes to the word processing document that address the accessed comment, and storing the one or more received changes to the word processing document in a document difference record associated with the accessed comment; receiving, from the reviewer, a request selecting a first comment from among the multiple accessed comments; and presenting, to the reviewer in response to the request, the word processing document and a first document difference record associated with the selected first comment, while hiding document difference records that correspond to unselected comments from among the multiple comments. 15. The system of claim 14 , wherein the operations comprise: receiving, from the reviewer, another request selecting a second comment from among the multiple accessed comments and unselecting the first comment; and presenting, to the reviewer in response to the other request, the word processing document and a second document difference record associated with the selected second comment, while hiding the first document difference record associated with the unselected first comment and any document difference records that correspond to any unselected comments different from the first comment from among the multiple comments.