lite___

Litematica is a new schematic mod written from scratch, and it is primarily targeting light mod loaders like LiteLoader on 1.12.x, Rift on 1.13.x and Fabric on 1.14+. There is also a Forge version for 1.12.2, but not yet for 1.14.4+ (but Forge ports for 1.14.4+ are also planned, see below).
It has all the features of the old Schematica mod except for the printer (which is not planned for Litematica itself, but instead is left to extension mods), plus a bunch more.

• The main feature of a schematic mod is to display a "hologram" version of a structure, which shows you exactly how to build the structure and where to place the blocks. It also includes a (configurable) overlay to highlight missing, extra or wrongly placed blocks.
• Litematica also includes a nice Material List, including a Material List HUD, to help you collect the materials needed for the build.
• There is also a Schematic Verifier feature, including an overlay, which you can use to scan the entire schematic area and look for any mistakes. This can be extremely useful especially with technical/redstone builds, where tiny mistakes can break everything.
• There are also several Creative-mode-only helper features, such as Fill, Replace, Delete and also a Paste mode for "pasting" schematics into the world (immediate/direct in single player, using /setblock commands in multiplayer).