Internet Explorer is a web browser developed by Microsoft since 1995 that was the most widely used until recently. It has gone through many versions and includes features like highlighting domains, a smart screen filter, and 128-bit encryption on secure sites. Mozilla Firefox is a free, open source browser that is also popular and includes private browsing, add-ons, and security features like malware protection. Google Chrome is a fast browser developed by Google that is also free and available on multiple platforms. It has gone through many versions since 2008.