Hiranthi

This plugin will help you to easily link to WordPress functions in the codex. Just put the function name between the [wp]function[/wp] shorttags and it’s linked to the page in the codex automatically.

Link to WordPress functions

Easily link to WordPress functions in the codex.

GKauten

Disables a collection of WordPress features that can help your blog run more efficiently and smoother. 
This includes functions such as the auto-save and revision tracking features used on the post and page 
editor sections which can help reduce database size by eliminating the build up of revisions which exist 
purely for administrative purposes and reduce server load. Other functions include the comment author URL, 
WordPress ‘Generator’ tag, and more.
Special thanks to John Blackbourn (http://johnblackbourn.com/) for his explorations of the Core Update system.

WP Feature Disable

Disables a collection of WordPress features that can help your blog run more efficiently and smoother.

Link to WordPress functions vs WP Feature Disable