Opera is a web browser and Internet suite developed by the Opera Software company. Opera handles common Internet-related tasks such as displaying web sites, sending and receiving e-mail messages, managing contacts, IRC online chatting, downloading files via BitTorrent, and reading web feeds. Opera is offered free of charge for personal computers and mobile phones, but for other devices it must be paid for. Features of Opera include high performance, tabbed browsing, page zooming, mouse gestures, and an integrated download manager. Its security features include built-in phishing protection, strong encryption when browsing secure web sites, and the ability to delete private data such as cookies and browsing history by clicking a button. Opera runs on a variety of personal computer operating systems, including Microsoft Windows, Mac OS X, Linux, FreeBSD, and Solaris. Although evaluations of Opera have been largely positive, Opera has had limited success on personal computers. It is currently the fourth most widely used web browser for personal computers, behind Internet Explorer, Mozilla Firefox, and Safari. Opera has a stronger market share, however, on mobile devices such as mobile phones, smartphones, and personal digital assistants.