Microsoft on Thursday released the final version for Internet Explorer 8 (IE8), signaling the company’s intent to take back market share it has lost to competing browsers, primarily Firefox, in the past few years.

The company’s market share with its aging earlier versions of IE has fallen in recent years from in excess of 90% to only 67 percent today, according to the latest global browser share figures from tracking firm Net Applications.

Dean Hachamovitch, general manager of the Internet Explorer team at Microsoft announced free downloads of IE8 are available as of Thursday morning. The announcement came at Microsoft’s MIX09 conference in Las Vegas.

In one major change from IE7 and IE6, Microsoft added a so-called “Super-Standards” mode that will render Web sites using the latest Web standards. That aims to enable sites that are tuned for standards support to properly display in IE8. At the same time, Microsoft came up with ways for owners of sites tuned to run in IE6 or IE7 to be able to tweak their pages to display properly as well.

Dot Eco LLC, the applicant for the new .eco top level domain, announced it has entered into an integrated partnership with former US vice president Al Gore and his philanthropy, the Alliance for Climate Protection (www.climateprotect.org), to secure and promote the .eco top level domain.

.eco will be established for individuals to express their support for environmental causes, for companies to promote their environmental initiatives, and for environmental organizations to maintain their websites in a namespace that is more relevant to their core missions. By charter, a majority of the profits of the .eco initiative will be distributed to support environmental causes.

“We fully support Dot Eco LLC in its efforts to secure the .eco top level domain through the ICANN application process and look forward to working with Dot Eco LLC to promote .eco. This is a truly exciting opportunity for the environmental movement and for the internet as a whole,” said Al Gore.

“The .eco initiative, as proposed by Dot Eco LLC, is a unique approach for fundraising for nonprofit environmental organizations such as ours. We are thrilled to be working with Dot Eco LLC to generate funds for our organization and to promote awareness of climate change.” added Cathy Zoi, CEO of the Alliance for Climate Protection.

“It is an honour and a privilege to be working with Al Gore and Cathy Zoi on the .eco initiative,” said Fred Krueger, CEO of Dot Eco LLC. “We are confident that we will generate substantial funds for the Alliance for Climate Protection to promote their efforts to increase awareness of climate change.”

“We believe that this initiative represents an example of the type of compelling top level domains made possible by ICANN’s new gTLD application process,” added Krueger.

The advisory board of Dot Eco LLC includes Davis Guggenheim (director of An Inconvenient Truth), Roger Moore (renowned actor and Goodwill Ambassador for UNICEF), Richard Muller (Author of Physics for Future Presidents and contributor to the Intergovernmental Panel on Climate Change) and Jim Dufour of the Scripps Institution of Oceanography.

Microsoft has included in recent Windows 7 test versions an option to turn off the Internet Explorer 8 web browser, according to testers who have used the recent builds.

Microsoft declined to comment on the feature’s inclusion as well as the reasons behind the move. Others are speculating it might have something to do with the European Union’s objection to the inclusion of a browser within Windows.

The software maker has cautioned that the EU may seek to have Microsoft allow PC buyers to choose their browser and then require Microsoft to disable certain IE code if a user chooses a non-Microsoft browser.