Starting a website for a product or a business is very simple and does not require many skills today. One can easily hire a web designer and get a really good website within a few days only. All that you need is an idea and some budget to fulfill all the requirements. It is becoming very popular to have your own search engine, especially on your website. Well, it all depends on the website owner and he can get any quality of search engine he wants. The quality, type, power and implementation of the search engine, all depends on the requirements of the owner.
It is a fact that most of the search engines now (especially those used on small websites) are fairly simple and small pieces of software that are created using very simply scripts and codes. However, it is also true that most of them perform very well, to a great extent, and do a good job in searching at least within the website for related content. So, it is useless to think of a big and powerful software or search engine to back up your searching needs if you run a comparatively small website.
Hardware: It is completely user-dependent and he can choose as good hardware as he can afford. In fact, a better hardware like servers and other devices would necessary increase the effectiveness of your search engine. So, keep this thing in mind while building your own search engine.
Software: You can have any type of software you can easily get. In fact, search engines like Google also provide you with free search engine resources that you can use and which will make your process of creating search engine a lot easier. You can even get their search engine installed on your website if you are not very much interested in getting one custom-built search engine.
In short, making a search engine is neither a very big deal nor very easy, in fact, it all depends on your specific requirements and needs