From Liquipedia Starcraft 2 Wiki
This is an all-in build which aims to kill a fast-expanding opponent before the opponent can reach a second tier of units . It relies on continual Marine reinforcements to cripple or outright kill the opponent. This build has small chance of being mistaken for a 1 Rax FE as there is no add-on on the first Barracks, with one Marine only, and the rest are placed well out of poking units sight range.
Punish an opponent for opening with an economic build or any that cuts early army size. Your reinforcements effectively limit their ability to spend money on anything other than an army, where you have the initial advantage.
 Build Order
TLO's Six Rax in Audio form: http://www.youtube.com/watch?v=6zc3RrQc5lM
|Basic Build Order|
With economic builds becoming more and more standard and early safe all-ins by Terrans becoming more rare, it is good to have a couple of deadly all-ins that 'keep the fear alive' by severely damaging or outright killing the opponent's fast expand. Even if the rush fails, an opponent may be thrown off of their intended tech path or build order by having had to deal with your attack.
- The attack starts as the opponent's natural expansion Hatchery finishes.
- Stop SCV production at 24.
- Kill or scare away any scouts before you start Barracks (2,3,4).
- Only engage one Bunker/Spine Crawler/Cannon at a time, or your Marine count will go down too quickly.
- Constantly produce Supply Depots, as each production cycle will fill available supply, Marines start the engagement.
- Spawning Pool timing in relation to your first Barracks.
- Cybernetics Core timing in relation to second Barracks.
- Bunker and Tech Lab placement.
- You want to engage with 12-16 Marines and retreat with about 5-6 Marines remaining.
- Keeping reinforcements back for the first engagement and reinforce with the third wave, and initially maybe mistaken for normal 2Rax Marine pressure poke.
- Stutter step micro to between mineral patches or against walls to reduce attack surface area of the melee units.
 Advantageous Features
- Any short rush distance (Steppes of War, Blistering Sands).
- Close positions on some 4-player maps (Metalopolis, Slag Pits).
 Disadvantageous Features
- Multiple attack paths available (Xel'Naga Caverns).
- Long rush distance (Tal'darim Altar).
- ScReaM v TLO cast by Husky
- IdrA vs TLO Part 1, Part 2, Part 3 Dreamhack Stockholm Invitational
- TLO vs Spanishiwa justin.tv Showmatch cast by Husky