This morning at Mozcon, I announced the launch of Open Site Explorer v3, a long-awaited upgrade to one of the most popular marketing tools on the web. I'm more than a little excited about all the progress, hard work and remarkable features that are included in this upgrade, so let's get right to them.

The first thing you'll notice is the new design (of which I'm a huge fan):

This continues into the top view of link data and now, social metrics. I've always wanted these to be side-by-side, and it's great to finally be able to see both at the same time.

The menus of filters have improved, and there's now a new visualization to show links as groups in domains or as separate links (like the classic Yahoo! Site Explorer view).

Social metrics are also included in the Top Pages reports, so you can see how the most-linked-to content has performed on the social web. This is particularly cool for popular blogs.

The anchor text and linking domains tabs have a new feature that lets you see a sample of the links that come from that domain (or with that anchor text). Beware that right now, there's a small bug where we're sorting those links we do show in some odd ways. This should be fixed in the next Linkscape update.

Comparison reports have also taken a nice step forward, and feature the ability to side-by-side compare metrics for pages, subdomains and root domains on up to 5 sites simultaneously. They match the metrics you can get in the PRO web app, as well, which is very cool.

And last, but not least, the new advanced reports tab lets you query like a SQL master! Without having to write any complex logic against our API (though you can still do lots of awesome stuff with that), you can grab any combination of link sorts, filters and keywords you'd like (and exclude data you don't want). This is particularly excellent for link builders looking at competitive or industry-related sites' link profiles, and I expect we'll see a number of blog posts in the near future with strategies on how to employ this tool.

In addition to all the amazing new features in Open Site Explorer, Linkscape's index just updated using a new infrastructure that's allowed us to crawl much deeper on large, important sites. For many pages/domains, this will mean an increase in the total number of links we report, but likely a lower count of linking domains (unless you've gained a lot of links in late June/July) since we're excluding many domains that are low-quality/not-well-linked-to. We'd love your feedback on this index, as it's the first one of its kind, and will continue to see tweaks/improvements over the next few updates.

• 58,273,105,508 (58.2 billion) URLs +47% from June (our largest index growth ever from one month to another!)
• 637,828,397 (637 million) Subdomains +71% (it appears the domains we're crawling have more subdomains)
• 91,013,438 (91 million) Root Domains -23% (due to the depth vs. breadth focus of this crawl)
• 456,474,577,597 (456 billion) Links +14%
• Followed vs. Nofollowed
  • 2.28% of all links found were nofollowed +5%
  • 60.44% of nofollowed links are internal, 39.56% are external
• Rel Canonical - 9.50% of all pages now employ a rel=canonical tag +20% (my guess is higher quality domains are more likely to employ rel=canonical)
• The average page has 78.64 links on it (+30% from 60.67 last index)
  • 65.33 internal links on average
  • 13.32 external links on average

We're looking forward to your feedback on the new features and the new index (which we plan to continue iterating upon). There's actually even more new features coming in September, so stay tuned and thanks so much for all the support and use of OSE; it's run more than a million reports, and we hope the next million are just around the corner.