My latest briefing of companies in the link building tools business was with Dixon Jones of Majestic SEO. In the near future I will publish a briefing about Wordtracker Link Builder
One of the things that distinguishes Majestic SEO is that they have a huge data set – more than 1 Trillion links are cataloged by them. They have also built in to the tool ways to process that huge mound of data so you can more easily extract meaning from it. Check it out!