Operating System
The operating system and web hosting software will be the most significant aspect of the successful and reliable hosting of your web site. The operating system is the core software which enables the server to run. This applies to any type of computer, not just servers. Your desktop PC would typically be running Microsoft Windows XP, Windows Vista or similar. In the same way, a server for web hosting has to have an operating system installed and running.
The most common types of server systems for web hosting are Microsoft, Windows 2000 or 2003, or "open source" software such as Unix or one of its derivatives, most commonly Linux.
In general, open source refers to any program whose source code (the program language code) is made available for use or modification as users or other developers see fit. (Historically, the makers of proprietary software have generally not made source code available.) Open source software is usually developed as a public collaboration and made freely available.
The Microsoft vs Linux debate is an on-going battle yet both have their pros and cons. The general opinion appears to be that the Linux/Unix platform is more robust. If you are outsourcing your web hosting via an ISP you may not have any choice. However, if you are co-locating or doing it in-house, then you will need to consider the following issues:
- Cost: Open source software such as Unix and Linux is, effectively, free, or at very low cost, but there is no formal support available. Microsoft products however have a cost, but support from the vendor is more readily available;
- Reliability: The general consensus is that open source software provides a more reliable system than that from Microsoft, which often requires the need to install "service releases" to fix known problems or bugs;
- Skills: There is a greater abundance of staff with knowledge of Microsoft products than those of other operating systems. This may be important when making your decision. Even if your server is hosted by an ISP there will be many occasions where technical work has to be carried out on the web site which involves knowledge of the underlying system;
- Features: There is a difference in the available features on each type of server. On a Microsoft server it is possible to host their database applications, Access for example. A Unix machine would require different applications. It is therefore important to decide on the intended function for the web site before making the decision;
- Security: This is a vitally important aspect of the hosting environment. Unix has a good track record of being secure from outside intrusions, viruses and having the flexibility to configure the system accordingly. Most outside attacks are aimed at Microsoft servers to exploit certain known vulnerabilities in the operating system.
On top of the operating system, sits the software which actually runs the web hosting. The most popular are Apache (Unix) and Internet Information Server - IIS (Microsoft). These will deal with all the elements of hosting the web pages, handling requests by visitors to see the web site, running programs or scripts and suchlike.