The opposite of transaction processing is batch processing, in which a batch of requests is stored and then executed all at one time. Transaction processing requires interaction with a user, whereas batch processing can take place without a user being present.

On Line Transaction Processing Integration and Development page
From Transaction Information Systems, this page provides links to an overview of transaction processing, as well as to their Level 8 Systems product.

Transaction processing and the Internet
A June 1996 PC Week article describing a new architecture from Progress Software, that will enable corporations to build and deploy database query and transaction processing applications on the Internet.

Transaction Processing Performance Council (TPC) home page
Provides information on transaction and database benchmark results, descriptions and specifications. Additionally, there are links to TPC organizational information and links to related Web sites.