Apache
Apache is the Web server for the Internet. Seventy percent of Web servers use Apache.
You can run Apache on every type of hardware that is useful for a Web server. You can use all the useful operating systems plus many others. You can use any file system supported by those operating systems. You can plug in every useful piece of Web software plus a whole lot of less useful stuff.
Conclusion
Replace Microsoft's IIS with Apache. If you also use ASP and Visual Basic, the conversion to PHP is easy.
