The GZCLP program is one that uses linear progression and was designed by Cody LeFever. It uses the 3 main lifts (Bench, Squats, Deadlift) - each done on a different day of the week. The program has been said to offer a balance between both the deadlift and squat (which is rather difficult to do). Not only that but eventually (as you learn about your body and what works for you) you will have a program that’s personalized to fit you.
GZCLP training is designed to be in tiers with there being 3 of them in total (Tiers 1, 2, and 3).

Where to get it / Who made it?
The program was designed by Cody Lefever and can be found here: http://swoleateveryheight.blogspot.com/2016/02/gzcl-applications-adaptations.html
Length of Program
GZCLP is broken into 3 week blocks and has 3 tiers. So it’s a 3 month program (or block).
Goal of the program/ Does it use RPE
It doesn’t (but can) use RPE but it does use percentages. The goal of the program is help lifters develop their sub maximal training weights which will help develop the 1 rep max. At the end of the cycle you can test or retest your one rep max.
Who’s it for?
Beginners/ Intermediate
How does the program work?
Essentially the lifter is supposed to take their 2rm and make that their 1rm for the training period. The cycles mentioned are each 3 weeks long with increasing intensity and lowered volume throughout the cycle.
Each tier (in a given cycle) requires the lifter to use a percentage of that 1 rm (2 rm) they chose and to take a percentage to lift for the rep range. An example of this would be below:
This goes on for the duration of the overall 9 week program. Cycle 2 increases the intensity of the program slightly for each week (and the same goes for the 3rd cycle). Aside from this the program allows the lifters to play around with the volume as long as it matches the base volume.
Accessory movements
Lifters do perform accessory movements in the second and third tiers but not the first (unless you add a fourth day and say that’s a day for an additional movement). So for the second tier on each day of the last week you performed a certain movement you’ll do something specific for each primary movement. So instead of squatting you’ll be front squatting. On the third tier you’ll be doing bodybuilding movements such as dips for chest instead of benching.
People using the program / Reviews for the program
Video credits to MegSquats
Video credits to Alan Thrall
Video credits to AM Training