>>Its not a matter of semantics per se, its a matter of mathematical definitions. The mathematical defintiion of mass does not change with velocity.
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>Sure.
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>I have catched up on my reading, and it seems that, indeed, the terms "rest mass" and "relativistic mass" are no longer very popular.
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>But the fact remains that the relativistic mass increases with speed, and whether you call it relativistic mass or energy, this is what will interact gravitationally with other objects.
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>The article at http://math.ucr.edu/home/baez/physics/Relativity/SR/light_mass.html , while explaining that (according to modern terminology) a photon "has no mass", it does have a gravitation attraction (small, because the - er - energy of a photon is usually insignificant). See especially the last paragraph.

Just to clarify: the last paragraph explains that gravity isn't an attractive force in general relativity, it is motion along curved geodesics. In other words, space-time is warped, and movement through warped space-time is what we call gravity.