Definition of "Life"

Then one deep love doth supersede⁠All other, when her ardent gaze⁠Roves from the living brother’s face,And rests upon the Life indeed.

1850, [Alfred, Lord Tennyson], In Memoriam, London: Edward Moxon, […], Canto XXXII, page 51

Basically, I'm looking for a fast (the fastest?) way of updating grids, where each cell has to look at an arbitrary number of its neighbors. I've seen some fast life-programs, but often they took advantage of particular quirks of the rules of Life.

1988 January 26, David Hiebeler, “Fast way to update grids”, in comp.theory.cell-automata‎ (Usenet)

Is there a known 3D totalistic or semi-totalistic automaton (Life is the latter sort - state at time t+1 depends on state at time t and count of neighbours) which exhibits the same sort of behaviour as Life (that is, a reasonable range of naturally-occuring still lives and short-period oscillators)?

1999 May 13, Thomas Womack, “3D automata with Life-style objects”, in comp.theory.cell-automata‎ (Usenet)

Maybe the RolfLife algorithm could be of value to someone implementing life i.e. in the vertex shader of a (DirectX 9) graphics card, where few lines of code and no LUT are favoured.

2003 February 20, Rolf Wilms, “Fast implementation of core algorithm for Conway's Game of Life”, in comp.theory.cell-automata‎ (Usenet)