The most used piece of software?
The Email Client

You basically have 2 choices:

• MS Outlook Express
• Thunderbird

Since you are probably using a Microsoft Windows operating system,
you probably are using Outlook Express.

If you are one of the lucky few using Linux
(the "other" operating system, that happens to be free.)
you can't use MS Outlook (yippee!!!)
instead you are already using Thunderbird.

I found the Internet back around 1995.
Netscape was the browser of choice.
It included a browser, email client, chat client and webmaster HTML page creator
Microsoft came out with their inferior browser but bullied market share, as usual.
Eventually, Netscape could no longer compete and AOL ended up buying the company.
AOL released the netscape browser to the open source community.
For many years I've used Mozilla (as it became known), both for browsing and email.
They've just released the new standalone email client call Thunderbird.
It's a great piece of software!

WizarDave highly recommends using the Thunderbird email client!

• It filters spam
• You will have fewer viruses and spyware problems
• It's available for ALL operating systems

Don't believe me?
Check out these Reviews:

• PC World says: Thunderbird 1.0 a Winner
  Mozilla's upstart e-mail program makes a strong case for dropping Outlook.
• PCmag says: "Editor's rating = Very Good"
• IT-Director.com says: [Thunderbird] is better than Outlook...it has all the features that matter.