Apache HTTP Server
The Apache HTTP Server, commonly referred to as Apache, is a web server software program notable for playing a key role in the initial growth of the World Wide Web. In 2009, it became the first web server software to surpass the 100 million website milestone. Apache has consistently been the most popular web server on the Internet since taking that spot from NCSA HTTPd back in 1996. Typically Apache is run on a Unix-like operating system, and was developed for use on Linux.
Apache is developed and maintained by an open community of developers under the auspices of the Apache Software Foundation. The application is available for a wide variety of operating systems, including Unix, FreeBSD, Linux, Solaris, Novell NetWare, OS X, Microsoft Windows, OS/2, TPF, and eComStation. Released under the Apache License, Apache is open-source software.
Apache was originally based on NCSA HTTPd code. The NCSA code has since been removed from Apache, due to a rewrite.
Since April 1996 Apache has been the most popular HTTP server software in use. As of June 2013, Apache was estimated to serve 54.2% of all active websites and 53.3% of the top servers across all domains.
IIS Internet information Services
Internet Information Services (IIS) – formerly called Internet Information Server – is a Microsoft web server software application and set of feature extension modules created by Microsoft for use with Microsoft Windows. IIS 7.5 supports HTTP, HTTPS, FTP, FTPS, SMTP and NNTP. It is an integral part of the Windows Server family of products (and their client counterparts in the cases of Windows NT 4.0 and Windows 2000), as well as certain editions of Windows XP, Windows Vista and Windows 7. IIS is not turned on by default when Windows is installed. The IIS Manager is accessed through the Microsoft Management Console or Administrative Tools in the Control Panel.