Abstract: Techniques are described for facilitating interactions between computing systems, such as by performing transactions between parties that are automatically authorized via a third-party transaction authorization system. In some situations, the transactions are programmatic transactions involving the use of fee-based Web services by executing application programs, with the transaction authorization system authorizing and/or providing payments in accordance with private authorization instructions previously specified by the parties. The authorization instructions may include predefined instruction rule sets that regulate conditions under which a potential transaction can be authorized, with the instruction rule sets each referenced by an associated reference token.

Abstract: A web site system provides functionality for searching a repository of information, such as the World Wide Web, by including a search string at the end of a URL without any special formatting. In one embodiment, when the system receives a request for a URL of the form www.domain_name/char_string, where char_string is a character string that may include spaces and non-alphabetic characters, the system initially determines whether the character string includes a prefix that identifies the URL as a non-search-request URL. If no such prefix is present, the character string is used in its entirely as a search string to execute a search, and the results of the search are returned to the user.