I'll start with a few. Just the basic steps though, not detailed or anything.
Petrus:
1.) Form a 2x2x2 block on any side
2.) Expand the 2x2x2 block to a 2x2x3 block.
3.) Orient all the edges.
4.) Finish the F2L, keeping edge orientation.
5.) Your choice of last layer method. Most popular is OLL and PLL.
ZZ(Don't know a whole lot about this):
1.) Orient all the edges on the cube and at the same time solve the DF and DB edges.
Not too sure about the steps after this, but I will do my best
2.) Solve the F2L on the left side. This can be done using R U and L turns only.
3.) Solve the F2L on the right side. I think this can be done using only R and U turns.
4.) Any last layer method you choose.
Roux:
1.) Make a 1x2x3 block on the left side of the cube.
2.) Make another 1x2x3 block on the right side of the cube.
3.) Solve the last layer corners. Can be done in 1 or 2 algs.
4.) Orient all the edges using only M and U moves. Only 6 edges total.
5.) Permute all the edges using only M and U moves. Only 6 edges again.
ZB:
1.) Solve the cross on the bottom layer.
2.) Solve the first 3 corner and edge pairs.
3.) Solve the last corner and edge pair while orienting all the edges in the top layer, using one algorithm. MANY to be learned.
4.) Solve the Last layer in one algorithm. Many more algs to be learned.
Those are pretty much the ones I really know about. There are many sub-steps that you can use though.
I am going to be mad if someone else has already posted this before me.