Internet Explorer (formerly Microsoft Internet Explorer and Windows Internet Explorer, commonly abbreviated IE or MSIE) is a series of graphical web browsers developed by Microsoft and included as part of the Microsoft Windows line of operating systems, starting in 1995. Internet Explorer has supported other operating systems with Internet Explorer for Mac (using Motorola 68020+, PowerPC) and Internet Explorer for UNIX (Solaris using SPARC and HP-UX using PA-RISC), which have been discontinued.