I would suggest using pre-made PHP scripts. Ofcourse, that does not mean that you will not require heavy duty servers!

I started building my Search in 1999.
Been debating Desktop search for some time at:
http://channel9.msdn.com/showuserthreads.aspx?userid=31672

It's the only program I really use.

It evolved to do all the search related features I could think of.

I have seen some script on the web some time ago, I think it is not hard to get the script and start the search engine but indexing webpages needs a lot of hardware. Another issue is how do you market your search engine and benefit from it as there are som many free search engines already availible for free?

But, if you make a search engine which can index and serve results for specific topic for example "golf tour search engine" maybe it can still grab a share in the market. Making general search engine and getting benefit from that is out off the question.

Out of curiosity, does anyone have a website who provide a already made search engine, maybe the Python or JavaScript for it?

Your own search web site could use existing search engines, and some kind of mask or skins, with customizable features to allow the user select between one or another, even several search engines, and how It will show the data in one web page.

If you are trying to create a search engine from scratch, you should begin creating your robo-spider first.