i am trying to implement a federated search. I have no idea how to start implementing it?
i have several questions relating to this.
1. has the application needs to be web based or desktop based?
2. do i have to have a database in the application side?

i would appreciate if some one could give me some hints to start this

hi what is the difference between a federated search and a search engin?
appreciate a reply,

I think the main difference is a federated search is more designed for databases and a search engine is more designed for the web. The federated search does the search by querying different databses with the same terms. A search engine uses a crawler to search and index all the information it can, then the search engine uses the index in compiling it's links.

Of course this is all my opinion for what it's worth :)

thank you tinstaafl.

i have another question too. How do i access a library database via an API? what language do i have to use. Will be helpful if someone can point me to some resourses thanks

In .net you can use several different languages to access databases, VB, C#, C++, the libraries are included I believe, it's just a matter of referencing them. Pick the language you feel most comfortable with. If you don't have much experience with these languages, I'd suggest VB. The language and syntax is more intuitive and forgiving. If you have a strong basis in C++, I'd suggest C#. The language and syntax is reminiscent of C++ but the intellisense in Visual Studio works very well with C#, making it much mnore intuitive. C# also has the advantage, from what I understand, of working better with ASP.net. Which is useful for web programming. Several different options and things to think about. Here's the main page for finding Visual Studio resources. This is all my opinion, for what it's worth. With this sort of thing, if you ask 10 different programmers you'll get atleast 20 different answers lol.

thanks tinstaafl,
so do you think that i should implement as a web page rather than a dektop application?
what would be easy?

Easy would depend on your experience. What would you feel more comnfortable with? If you're learning a new language and new techniques, you may find yourself overwhelmed with the complexity involved. Also if you stay in .net most, if not all, of the techniques can be transported to any of the supported languages if needed. You can even use code from other languages in one solution.