File Viewer:
Puts the content of a specified file into an HTML element.
Voting form:
When a user submits a vote, the form is instantly replaced by the actual voting results (instead of using popups, or reloading the whole page).
Chatboard:
A messagebox where the visitors or users can communicate with each other.
Text content editor:
This application lets you edit the content of a text document by adding/editing pages, paragraphs, etc.