Keywords and keyword density are common terms in SEO. You want to know your keywords and keyword density for your Web pages and your competitor pages. SEO Keyword Spy is a PHP class you can plug in to your programs that saves you time with keyword analysis functions. The tool even has a graph you can use to print out analysis and display it on the screen, or you can retrieve the keywords and use them in your own programs.
– Retrieve keyword phrases from a URL
– Get percentages…