Companies that claim to improve Perl ranking through various ways of fooling google charge thousands of dolars per consultation. Even then they can't guarantee that a site's favorable position in the rankings for a given search term will remain constant through google's next reorganisation of it's ranking algorithm. While the general outline of their algorithm is public, the exact details are closely guarded. After all, any of the "improve your pagerank" companies that knew the exact details could fool the spiders in placing all it's clients on the top of relevant search lists, making a lot of money and devaluing google's utility in the process.

Google frequently tweaks their algorithm precisely because they don't want to reward people who abuse their engine with generated-for-google pages, (or worse yet, webs of pages).

In fact, if you perform a search and find clearly fraudulent results, click on the "Help us improve" link at the bottom of the search page, and fill out the form. I understand google's engineers are pretty good about lowering the ranking of frauds reported through that page.

The page rank of a particular site depends on the quality of content on that site, on the relevance of content (how similar the pages pointed at are to the links pointing at them), to the page rank of pages pointing at that page, and last, but not least, the number of pages pointing at the site. (And probably many more factors we can only guess at).

So Perlmonks rates high because a lot of high-quality pages point at various points within the monastery, and the monastery scores high on the relevance, and low on "fraudulence indicators", the .pl in the URL nonwithstanding.