The AppleSearch Server needs to run on a Macintosh computer that supports AFP (AppleTalk Filing Protocol) and PPC (Program to Program Communication).
The AppleSearch client software initiates the search on the AppleSearch Server via PPC in order to isolate the data handling on the server and optimize performance. (For this reason the data and indexes must reside on the AppleShare Server itself.) AFP is used to transfer the search results back to the client software.
At this time only Macintosh computers running System 7 File Sharing, AppleShare 3.0x, AppleShare 4.0, or AppleShare Pro can function as AppleSearch Servers.