The long-standing model-independent annual modulation effect measured by DAMA deep underground at the Gran Sasso National Laboratory (LNGS) of the I.N.F.N. with different experimental configurations is summarized. In particular, the DAMA/LIBRA--phase2 apparatus, $\simeq$ 250 kg highly radio-pure NaI(Tl), profits from a lower software energy threshold with the respect to DAMA/LIBRA--phase1. DAMA/LIBRA--phase2 confirms the evidence of a signal that meets all the requirements of the model independent Dark Matter annual modulation signature, at 11.8 $\sigma$ C.L. in the energy region (1--6) keV. In the energy region (2--6) keV, where data are also available from DAMA/NaI and DAMA/LIBRA--phase1, the achieved C.L. for the full exposure (2.86 ton $\times$ yr, 22 annual cycles) is 13.7 $\sigma$; the modulation amplitude of the {\it single-hit} scintillation events is: $(0.01014 \pm 0.00074)$ cpd/kg/keV, and the measured period and phase are well in agreement with those expected for DM particles. No systematics or side reaction able to mimic the exploited DM signature (i.e. to account for the whole measured modulation amplitude and to simultaneously satisfy all the requirements of the signature), has been found or suggested by anyone throughout some decades thus far.