There are 4 major types of software fault tolerance mechanisms: rollback/retry; recovery blocks; multiversion software; replicated primary/copy; and distributed recovery blocks. All methods have strengths and weaknesses in terms of resource requirements, response time, and breadth of coverage. This technology allows the integration of these methods to allow systems to transition from one mechanism to another based on a predefined adaptation policy. We have applied the adaptive fault tolerance scheme to the domains of both command and control and deep space unmanned vehicles.