H1,H2 and H3 are feet of altitudes, M1,M2,M3 are midpoints. H is the orthocenter. X2,X3,Y1,Y3,Z1,Z2 are formed by reflecting H1,H2 and H3 in the other altitudes. X,Y,Z are the intersections between the lines joining midpoints to these reflected points.
Observe that H appears to be the incenter of XYZ so long as ABC is acute angled.
Otherwise it appears to be one of the excenters