Opera is an internet suite consisting of a web browser, an email client, a chat client, and a contact manager. The Opera web browser is usually hailed as an innovative and secure web browser, with many popular features of modern web browsers being Opera innovations. Additionally, Opera has a better security record than any other browser for Microsoft, Macintosh, and UNIX-based operating systems. Traditionally, the Opera suite was funded by the user's choice of either paying for the software, or having ads displayed in the browser. Since version 8.50, released in 2005, Opera is free to download and install on any supported operating system. It is not, open source, however, which some people claim is the only barrier preventing it from overtaking Firefox as the leading non-Microsoft web browser.
Many of the newest features of today's web browsers have been present in Opera for years. The tabbed browsing feature of Firefox and IE7 has been present in Opera since 1994, and features such as search aliases, page zoom, sessions, and user-defined stylesheets were introduced in Opera in the mid-1990's. Even Firefox's acclaimed "Clear Private Data" feature has been standard in Opera since version 4 was released in 2000. That same year, Opera released the fifth version of the web browser that shipped with features such as mouse gestures, integrated search, and popup blocking, all standard features on today's browsers.
Opera's security record is not only the best of any available web browser, it is also better than almost any other software in any category. While vulnerabilities have been found in the web browser, they are usually patched within days of being discovered. This is in contrast to the 23 day exploit-to-patch average for Internet Explorer. Of course Opera, like Firefox, is invulnerable to attacks aimed at ActiveX or other Microsoft-proprietary features. And malicious software cannot automatically download and install itself when a user browses with Opera. That said, Opera may be considered to be less vulnerable to exploits than other web browsers as it is deemed less of a target than more popular web browsers. If more people were to use Opera, some claim, then the writers of malicious software would code specifically for it.