Xobni is a San Francisco-based email startup. It was founded in March 2006 by Adam Smith and Matt Brezina from Adam’s dorm room in Cambridge, Massachusetts as part of the Y Combinator summer founder’s program. In late 2006, it relocated to San Francisco when the founders felt that the environment there was more suited to grow their company.

In March 2007, Xobni raised US$4.26 million from Khosla Ventures, First Round Capital, and Atomico, along with a number of angel investors.

Xobni’s first product, Xobni Insight, was launched into private beta on September 18, 2007, at the TechCrunch 40 conference. Xobni Insight plugs into Microsoft Outlook and offers fast search and people-based navigation of email archives. The company has hinted at plans to offer the same functionality for other email clients. Xobni Insight has received mostly positive coverage, although initial versions had performance problems on large inboxes. The company opened its beta to the public on May 5, 2008 and has since garnered media coverage from a number of blogs and media outlets such as The Wall Street Journal, The Boston Globe and Cnet.

In February 2008, Xobni hired Jeff Bonforte, a Vice President at Yahoo!, as their CEO. In the same month, Bill Gates gave a demo of Xobni at the Office Developers’ Conference. This led to rumors of a US$20 million acquisition by Microsoft, which the company reportedly rejected.

Cisco Systems, which has been expanding its workplace collaboration tools, has taken an interest in Xobni. Xobni announced on January 5, 2009 that it closed a $7 million round of financing, its second, with Cisco as a new investor. The company’s previous investors Khosla Ventures, First Round Capital, Baseline Ventures and Atomico also participated. The website CrunchBase has total funding at $14.6 million for the San Francisco based software development company.

There have been a lot of questions since the product release of how Xobni planned to make money and the scope of their products. In July of 2009 Xobni released a paid version of its product called Xobni Plus, offered initially for $30. Xobni Plus includes features such as advanced search, appointment search, the ability to search multiple PST archives, no ads, and one year support. In Free Studio version 4.2 Xobni is included in the .exe setup.

“Xobni” is the word “inbox” spelled backwards. It is pronounced Zob-nee.

Size : 6.3 MB

Mozilla Thunderbird is a free, open source, cross-platform e-mail and news client developed by the Mozilla Foundation. The project strategy is modeled after Mozilla Firefox, a project aimed at creating a web browser. On December 7, 2004, version 1.0 was released, and received over 500,000 downloads in its first three days of release, and 1,000,000 in 10 days.

Size : 8.8  MB

Yahoo! Messenger is an advertisement-supported instant messaging client and associated protocol provided by Yahoo!. Yahoo! Messenger is provided free of charge and can be downloaded and used with a generic “Yahoo! ID” which also allows access to other Yahoo! services, such as Yahoo! Mail, where users can be automatically notified when they receive new email. Yahoo! also offers PC-PC, PC-Phone and Phone-to-PC service, file transfers, webcam hosting, text messaging service, and chat rooms in various categories.

Yahoo! Messenger was originally launched under the name Yahoo! Pager on March 9, 1998.

In addition to instant messaging features similar to those offered by ICQ, it also offers (on Microsoft Windows) features such as: IMVironments (customizing the look of Instant Message windows, some of which include authorized themes of famous cartoons such as Garfield or Dilbert), address-book integration and Custom Status Messages. It was also the first major IM client to feature BUZZing and music-status. Another recently added feature is customized avatars.

Size : 16.8  MB

Released in 2007, ooVoo is an audio and video instant messaging client for Windows and OSX, and is similar to Apple’s iChat, with the advantage of being cross-platform. Calls can be recorded in real time. Like in Skype and Goober, up to 6-way video chatting is supported (but not a free feature). ooVoo provides real-time comments and warnings about performance and usage and has a connection speed display that gives an indication of latency.

Size : 17.5  MB

Google Talk (GTalk) is a free-of-charge (but proprietary software) Windows web-based application for instant messaging and voice over internet protocol (VOIP), offered by Google Inc. The first beta version of the program was released on August 24, 2005.

Instant messaging between the Google Talk servers and its clients uses an open protocol, XMPP, allowing users of other XMPP/Jabber clients to communicate with Google Talk users. VoIP in Google Talk uses an older version of what would later become the Jingle protocol. The technology used within the Google server network however is not publicly known.

The Google Talk client is only available for Microsoft Windows (2000, XP, Server 2003, Vista and Windows 7), but Google Chat (voice and video chat) is now available for PCs and Intel-based Macs. Google Talk mobile clients are also available for the Palm Pre, BlackBerry, iPhone, Android-based devices and is preloaded on the Nokia N900 smartphone. With the release of the Google Talk gadget, users of all platforms supported by Adobe Flash Player can also use Google Talk. Many other XMPP clients are compatible with Google Talk, and support a variety of other platforms.

Size : 1.6  MB