In an embodiment, a system is configured to replay and/or reconstruct execution events and system states in real time or substantially in real time starting from the point when execution of a target program has stopped to the point when the user desires to step through the target program's execution in order to debug the software. In an embodiment, a system is configured to efficiently collect trace data that is sufficient to reconstruct the state of a computer system at any point of time from the start of execution to the time execution was stopped. Efficient and effective debugging of the software can be performed using embodiments of the disclosed methods, systems, and devices.