Shoutbox by Siropu 1.5.7

This is a shoutbox widget that you can add in any of the available widget positions.

Options:

1. Minimum age required - Enable shoutbox based on user's age.
2. Shoutbox refresh interval - Allows you to set refresh interval for new messages. This option can be disabled.
3. Shoutbox refresh timeout - Stop refresh interval for inactive users after x minutes
4. Maximum shout length - Set the maximum allows shout length.
5. Minimum time between shouts - Flood check (with user group permission to bypass it)
6. Shout display limit - Set the maximum number of shouts to display on page load.
7. Delete shouts older than - Allows you to auto-delete shouts older than x days.
8. Auto prune shoutbox every x hours.
9. Auto prune message.
10. Enable navigation tab - Allows you to chat in a dedicated page
11. Enable sound - Enable sound notification for new shouts.
12. Enable avatars - Display user avatar in shout.
13. Allow BB codes - Controls if BB codes are parsed or not.
14. Enable auto link - Auto link/embed URLs and media sites.
15. Enable smilie button - For easy smilie access.
16. Reverse ordering - Place input box at the bottom and display new messages from the bottom to the top
17. Quick user tagging button with shout highlight.
18. Footer - Allows you to add custom content (text, ads, etc) in the shoutbox footer.
19. Thread ID - Post shouts in a dedicated thread as well.
20. Thread message minimum length - Set minimum length required for shouts.
21. Ban users with ban list
22. Archive with option to search by user and keywords

It has user group permissions for using shoutbox, editing/deleting shouts, prune shoutbox (/prune)
When scrolling at the bottom of the shouts, older shouts will be automatically loaded.

If you want a feature rich chat application, please see my Chat 2 add-on.
Shoutbox demo is available here: https://www.siropu.com/forums/