The Apache HTTP Server, colloquially called Apache, is the world's most widely used web server software. Originally based on the NCSA HTTPd server, development of Apache began in early 1995 after work on the NCSA code stalled. Apache played a key role in the initial growth of the World Wide Web, Apache is developed and maintained by an open community of developers under the auspices of the Apache Software Foundation. Most commonly used on a Unix-like system, the software is available for a wide variety of operating systems, besides Unix and GNU+Linux, including eComStation, Microsoft Windows, NetWare, OpenVMS, OS/2, and TPF. Released under the Apache License, Apache is free and open-source software.