This paper describes the concept of Time-Machine Computing (TMC), a time-centric approach to organizing information on computers. A system based on Time-Machine Computing allows a user to visit the past and the future states of computers. When a user needs to refer to a document that he/she was working on at some other time, he/she can travel in the time dimension and the system restores the computer state at that time. Since the user’s activities on the system are automatically archived, the user’s daily workspace is seamlessly integrated into the information archive. The combination of spatial information management of the desktop metaphor and time traveling allows a user to organize and archive information without being bothered by folder hierarchies or the file classification problems that are common in today’s desktop environments. TMC also provides a mechanism for linking multiple applications and external information sources by exchanging time information. This paper describes the key features of TMC, a time-machine desktop environment called "TimeScape", and several time-oriented application integration examples.