InterFormNG2 contains an Audit log. In this log the major changes are logged. This includes:
Creation, modification and deletion of library resources (including templates modified in the designer).
Creation, modification and deletion of workflows.
Creation, modification and deletion of users.
It does not include a backup or versioning of the old resources, but it does trace who did what and when.
The audit log file is stored as a file in this path as default:
C:\ProgramData\InterFormNG2\profiles\default\logs
Here the audit file is stored as interformng2_audit.log.
You can see the contents of the file either via file explorer or by signing on as a system administrator, select system Admin, and here select System logs and the audit log file on the top left like below: