Portable Document Format (PDF) is one of the best way to read huge documents online or offline and many publishers of books create PDF versions of it which can be found on the Internet. You can definitely use Google to find many such PDF files but the fact is that having something more granular would be much more efficient.

PDF Search Engine is a speciality search engine to find and download PDF files. You can search for PDF files just like you search in your regular search engines, but the difference is that the results will only show you links to PDF files which you can download and read at your own leisure.

What We Liked About PDF Search Engine

We put the search engine to a little test and were happy with the results we got. The search term we used was Composite design pattern, we got quite a few results many of which matched our search keywords.

We were also impressed by the fact that they directly link to the PDF files rather than us having to visit any website and then download it.

What We Didn’t Like About PDF Search Engine

The titles of the search results are bound to cause confusions and PDF Search Engine needs to definitely improve on those. For example we searched for ORiellyone of the biggest publishers of technology books and came across several results. But there were some misleading titles such as Apacheand Web2.0which are deceptive with regards to what the actual content might hold. It could be a book Apache Web Server or it could be Apache’s Tomcat or it could be Apache’s Axis. The only way to know what the book holds is after you download it.

PDF Search Engine also needs to add in support for human queries rather relying on known terms, for instance the keywords Composite design patterndid return satisfactory results but a search for the keywords Composite design pattern in javadid not fetch any results at all. Though design patterns are not isolated to Java itself there are many authors who write design pattern books specific to languages.

Can We See Legal Issues With PDF Search Engine?

Looking at the Terms of Use of PDF Search Engine we were a bit surprised that they put the onus of Copyrights on the user rather than themselves. Here is a excerpt from their TOU.

pdf-search-engine.com offers its files search technology on an "as is" basis. pdf-search-engine.com distributes information supplied by third parties and provides Internet links and references gathered from outside sources. Therefore, you should not assume:

……

that your use of the service will be uninterrupted, or that the material linked within the pdf-search-engine.com database is not copyrighted

This is bound to be a problem for users since ORielly and for that matter Manning Publishers PDF’s (which are available) are copyrighted and they are available through PDF Search Engine. A definite sore point which is legally valid and many so called search aggregating websitesfollow with a disclaimer saying it is up to the users to act on any copyrighted materials.

So before you start downloading books I highly suggest you read their terms of use just to stay safe as they put the onus on the user. Sadly there is no way to determine what is copyrighted and what is not.

Summarizing

Overall this is a good service since it isolates to only a certain type of search but there is still some time till we can actually make it a one stop search for PDF documents. We also love the direct download feature as it is convenient and saves us lot of time.

The fact that we have to look to avoid downloading copyrighted material is what will keep us away from this service till they take the onus on themselves and start removing the copyrighted materials from their search results, till then it’s good old Google.

Do you use any PDF search engines other than Google? Do let us know through your comments. Also try this service out and let us know how it works out for you too.