This is a WordPress plugin called User Voices. It allows each author to have their own CSS style. Authors can collaborate on a single post and attribute each section to a different user.
Install this file by copying it into your wp-content/plugins directory.
Modify your style sheet. (This can be done with WordPress's Theme Editor). Add the following CSS declarations:
/* Replace login with the login name of a WordPress user. */
.author_login { /* Set properties that apply to entries by a certain author. */ }
.voice_login { /* Set properties that apply to sections of entries that have been attributed to a certain user. */ }
You can also use grouping or other CSS syntax to form useful declarations. For example, here is a simple snippet that causes interjections to be italicized.
/* Authors' words are normal. */
.author_chad, .author_elisa { font-style: normal; }
/* Interjections are italicized. */
.voice_chad, .voice_elisa { font-style: italic; }
/* Interjections by the authors themselves are normal. */
.author_chad .voice_chad, .author_elisa .voice_elisa { font-style: normal; }
When writing posts, you can mark sections of the entry with a voice of another user. Hilight the section that you would like to change. Then, look for the drop-down menu labeled "-- Styles --". Select from the list a WordPress user. Finally, save the post.
The following image shows the User Voices plugin being used for a new entry. A section of the text was hilighted in the edit window. Then a style was chosen from the available users listed in the drop-down menu.