This is the latest stable released version of N.I.N.A.
The version did undergo a fair amount of testing and is stable to use for your imaging runs.
Version 1.8 HF1
The beta and release candidate version contains all the new features, bugfixes and enhancements, that are going under a careful test in order to be released for a new released version. Increments of this bundle will contain bugfixes that are found during testing. As no new features are added during the tests, these builds are rather stable and should not contain any major issues for your imaging runs.
Version 1.9 BETA005