CraftTweaker

This review covers 1.12.2 only.

It's old, it shows its age, and it was incredibly sexy back in its heyday (and some people swear up and down that it still is): this dev tool is the definition of a silver fox.

CraftTweaker is, at its core, a recipe editor. Using it requires the use of a custom scripting language designed specifically for the mod called ZenScript, the documentation for which is fairly good (provided you know how programming languages work already).

Pros:

• out of the box, the capabilities of the system are highly expandable via the use of ZenClasses and native method access. With addons, you can edit the recipes from even more mods.
• literal decades of documentation on how to use, abuse, and expand the core functionality, most of which is collated on a single webpage (the official CrT documentation)
• mountains of example scripts to crib from in modpacks like E2E:E, ROTN, and SevTech

Cons:

• requires learning an entirely new language (ZenScript), as opposed to just using Java (which minecraft developers should already know) the way GroovyScript (the main only competitor to CrT on 1.12) does
• ZenScript has technical limitations that make doing certain things unintuitive or outright impossible: this problem cannot be fixed due to the design philosophy and technical debt of ZS itself
• significant load time cost as some things can't be hotloaded after editing files (this is a technical limitation whose blame is split between minecraft itself, the zenscript interpreter, and the jvm they both live in)

I first used CraftTweaker way back on 1.7.10 (so like, 12 years ago now lol) - and maybe a bit on 1.6.4, but I don't remember - and figuring out how to use it & HQM is what got me into making modpacks (and now i've made about a dozen bad ones lol).

CT is a very straight-forward mod to use, but on modern versions it's fallen out of favour due to the number of mods removing support for it (and the lack of add-ons that re-add said support). KubeJS is the go-to for 1.18+ nowadays, but I'll always remember CT since it was a key part of my modpack development journey.

First of all, this review mainly targets the 1.12.2 and below versions of CraftTweaker.

CraftTweaker has awesome features helping you create the modpack you want to create. It has tons of options like replacing ingredients in every recipe, which can be used to allow plug and play with some mods even in total conversion modpacks.

It has an awesome documentation that, unlike KubeJS (at least from what I could find), also covers 1.12.2 and other versions. What's even better about CT is that it still gets updated on older versions.

I have to remove one star for gameplay since you have to restart your modpack every time you change something in order for it to take effect on 1.12, which CT blames Minecraft for, but there are some other mods which apparently can still reload on this version.

CraftTweaker, at least on the newer versions, is capable of a lot more, has an abstraction layer to deal with recipes, and is a lot easier to use compared to KubeJS.