Inspired by a popular Sphinn submission which touted 101 Free SEO Tools that don't suck, Tad Chef over at SEOptimise compiled his own list.
The 30 Free SEO Tools You Must Know.

Here's why he compiled his list:

Using 101 tools for whatever purpose is not productive. At the end of the day you got to find your set of say 10 or 12 tools you’ll use. Everything else is just playing around and wasting your precious time.

Here's what's on it:

  • web based tools
  • stand alone software
  • Firefox extensions

Do you have a quick list? What's on it?