Data available prior to 1991 for the Ga-Ni and Ni-Sn systems were critically assessed by Nash [1991Nas] to develop the phase diagrams (Ga-Ni, Fig. 1; Ni-Sn, Fig. 2) for the two binary systems. These diagrams were included in the compilation of Massalski and Okamoto [Massalski2]. Similarly, data for the Ga-Sn system were assessed by T.J. Anderson and I. Ansara, but their Ga-Sn phase diagram was not published elsewhere before inclusion in the Massalski compilation. The Ga-Ni diagram [1991Nas] shows eight intermediate phases: GaNi3 (b1), Ga3Ni5 (d¢), Ga2Ni3 (HT) (e), Ga2Ni3 (LT) (c¢), GaNi (m), Ga4Ni3 (/), Ga3Ni2 (b¢), and Ga4Ni (q), of which m melts congruently at 1220 C. The b1, b¢, q, and (Ga) phases form through peritectoid reactions: L + cM b1 at 1212 C, L + mM b¢ at 895 C, L + b¢M q at 363 C and L + qM (Ga) at 30.2 C; here c is the fcc terminal solid solution (Ni). The e, d¢, and / phases form through peritectoid reactions: b1 + mM e at 949 C, b1 + eM at 741 C, m + b¢M h at 542 C. The eM c¢ phase transformation occurs near 680 C. A eutectic reaction LM b1 + m occurs at 1207 C. The Ni-Sn system [Massalski2] (Fig. 2) has four intermediate phases, Ni3Sn (HT) (p¢), Ni3Sn (LT) (p), Ni3Sn2 (e1), and Ni3Sn4 (q1) of which p and e1 melt congruently at 1174 and 1264 C, respectively. A polymorphic phase transition p¢M p occurs at 977 C. There is also evidence for a transition in the e1 phase, but the transition temperature and the nature of the transition are not well defined. The q1 phase forms by a peritectic reaction at 794.5 C: L + e1M q1. Three eutectic reactions occur: LM c + p¢ at 1130 C, LM p + e1 at 1160 C, and L M q1 + (bSn) at 231.5 C. Two eutectoid reactions also occur: p¢M cM c +M p at 920.5 C and p + p+ e1 at 850 C. The Ga-Sn system [Massalski2] system in Fig. 3 is a simple eutectic system with the eutectic composition at 8.4 at.% Ga and the eutectic temperature being 20.5 C only slightly above the Sn transition temperature at 13 C.