Search for “tools for SEO” and, among the results, you’ll find “29 best free tools,” “the top [number goes here] SEO tools you should be using,” and many many more headlines following this formula.
But if you’re serious about Search Engine Optimization, managing a large enterprise program for a brand, for example, you may be looking for something more substantial to guide your tool evaluation process. We’ve spent the last few months on a resource that I know you’ll find really useful.