An information processor for information registration, capturing means captures a graphics processing command, and database registering means registers, as information about completed work in the database, information about a series of graphics processing commands concerning completed works out of the captured graphics processing commands. In an information processor for information retrieval, proceeding work detecting means detects a work in progress as a proceeding work based on the captured graphics processing command, and information acquiring means searches a database for the information about the work in progress which has been done before based on the graphics processing command concerning the proceeding work and acquires the information about the work in progress which has been done before.