Interlinking Plugin

Anybody knows of a plugin that can insert interlinks for desire keywords and URL? But is not dependent on the plugin and that it inject the links on keywords permanently.
Similar to the SEO smart Links but it will inject the link and update each post so that links are hard coded on the post. I have used similar plugin like SEO smart links and it slows down the site when too many links are place.

See original post by point2