There is an absolutely definitive answer: search engines see pages. Search engines do not see the code that produces pages.
I remember the day when "web developers" first concerned themselves about oh, performance, database connectivity, effeciency, code reuse... now we worry about search engine "optimization" before even learning the most fundamental first principles of web development, such as the difference between "client" and "server".
Slightly OT, one thing you might consider is that search engines don't tend to carry results like http://www.example.com/products.php?category=5&id=6. Instead, you might want to use something like mod_rewrite (if you use Apache) and have your links point to http://www.example.com/products/5/6 instead, and have mod_rewrite re-write it to the original URL. That's a negative effect of these scripting languages. Back to the original question, it then doesn't matter what language you use, as the search engine won't even know you're using php (well, they can find out under normal config, but you can disable things like that too (php.ini expose_php setting)).
That's simply not true. Bots can follow parameterized links just fine. Nor do they have access to configuration files. I'm sure you mean well, but spreading "SEO" rumors and mis-information is not helpful.
I disagree! Nearly all bots can follow paramaterized links just fine. However, they are aware that they are dynamic URLs and are often much more reluctant to include them. MCP was right in stating that "search engines don't tend to carry results like" ... he said nothing about having a problem following them.
Based on what evidence? I know you use mod_rewrite here, but I don't on my forum, and when I do a targeted search for specific pages, there isn't an issue finding them. I think this is one of the great myths of SEO.
Search engines will index any page that has a query string with the she same results as a page without a query string. The only time a query string will cause SEO issues is if it contains a session ID or id= in the query string (because that can be perceived as a session ID). Otherwise there is no difference between the two as far as getting pages indexed.
Keep in mind, though, that "PageRanks" have very little to do with actual search engine results, the indexing of the pages. All search engines can and do index parameterized URLs, so there should be no excessive hand-wringing in regard to dynamically-generated pages with PHP and/or ASP.
Sorry, I place very little credence on anything Google says regarding "Search Engine Strategies". To essentially claim that their own bots are so flawed that they can't follow perfectly valid links, or that they can follow those links, but gosh, just can't index them properly, is just too ludicrous for words. They have a vested interest in the SEO-industry, which is more or less synonymous with the AdSense industry. They have a history of double-talk and obfuscation on the topic.
I believe what I see, and again, targeted searchs return pages with querystrings just fine.
Wow, talk about topic hijacking. I was ready to answer the PHP/ASP question but see that the question is completely different.
The correct term, nsrajesh, is "sandboxed." Typically, this is a 9-month period (it varies, though) where you don't get indexed because of the trust that Google has to place on your site. Factors involved in rankings include date of domain creation, content updates, and inbound links. All of this will help you build over time, but you typically don't get listed immediately. You need to be *very* patient.
This is getting to be a tired argument between us, but I still believe that simple .html pages do better than query stringed pages.
Something else I'm against are keywords in the URL. There is nothing worse than using vBSEO (for a forum, at least) and keyword stuffing each page like list-of-my-keywords.html. If everyone agrees that keyword stuffing in the actual pages is not good, why would they all think that keyword stuffing in the URLs is great??
As for why I am so confident in all of this? Experience.
When I purchased PFO from Kyle last month, he couldn't get the number of pages indexed in Google above 6,000 after trying for two years straight, despite using vBSEO. I used my vB hack on the site, changed the directory structure, and DIDN'T use 301 redirects (I purposefully wanted to start with a completely clean slate), and we were completely reindexed with 11,000 pages after 48 hours. A month later and we have 36,000 pages indexed in Google.