This mod adds curvy pipes to Minecraft, with a powerful editing system that allows you to create a network of curves and branches. The mod provides timely support and updates for a wide range of Minecraft versions, ranging from 1.7.10 all the way to 1.21.1

Curvy pipes have full collision physics support. Here's a circular animal pen made of pipes, and a ramp you can walk on.

Pipes from this mod aren't block-based: you can fit multiple pipes within the same block space, or even share space with other mods' blocks. Tiny pipes can fit inside the 3-pixel gap above a create depot:
Pipes sharing space with other blocks

Performance

This mod is optimized for both FPS and TPS, with core algorithms implemented in native code and VM/native crossings carefully minimized. As of version 1.2.2, it should perform similarly or better than other block-based logistics mods.

Functionality

Both item pipes and fluid pipes can filter and regulate the amount stored in the attached inventory. Item pipes can either actively push items to other pipe ends (Extract), or actively pull items from other pipe ends (Retrieve).

The pipes have accurate throughput: the thinnest pipe in a series of pipes does form a bottleneck, and branching out to parallel pipes then reconverging is identical to having a single thicker section. Pipes can pass through unloaded chunks, and will function normally as long as the machines they attach to are loaded. New in 1.14.0: item pipes can be made transparent by right-clicking with glass. Items still transfer instantly and do not actually stay inside pipes: the traveling items displayed only serve as a visual clue of past transfers. Item rendering is currently unoptimized so do not overuse transparency.

Applied Energistics (AE2) integration: if you have AE2 installed, all types of ME cables can be made curvy by using them in off-hand (or left-click toggle in 1.7.10). You can connect curvy ME cables directly to cable parts (e.g. buses & terminals). The curvy ME cables work similarly to the original cables: curvy quartz fibers can be used to segregate networks, and curvy smart cables will display the channel count in-world.

New in 1.11.3: curvy ME cables can now attach to the lateral sides of cable parts, not just the back side. This allows creating extremely compact setups. Below on the right, there are 3 independent lines of cables and 2 pattern providers all inside the same block space; on the left, 4 dense cables are fitted inside a single block, carrying 128 channels.
Compact AE2 Setup

GregTech Integration: if you have GTM (1.20.1+) or GTCEu (1.12.2) or GT5u (1.7.10) installed, all GregTech's EU wires and cables can be made curvy by using them in off-hand (or left-click toggle in 1.7.10). The curvy cables work similarly to the original cables: they have EU loss as shown in the tooltip, and will burn up if you overload them. Similarly, all item and fluid pipes from GregTech can be made curvy, and the fluid pipes will follow the same temperature & material restrictions specified by the GregTech pipes.

New in 1.8.0: Added an optional grid system that helps aligning pipes to regularly spaced points. It can be enabled by middle-clicking empty space.
Alignment Helper

New in 1.5.0: Added radial menu for editing nodes. By inserting / moving / deleting nodes, existing curve shapes can now be modified without needing to break the pipes. Pipes can also be reattached to another block while preserving its configurations.

New in 1.13.0: Added redstone cable that conducts weak redstone signal just like vanilla redstone wires, but uses Curvy Pipes' grid-free system. (Video)

This mod is still in active development. A more advanced logistics system, more performance optimizations and integration with other content mods are planned for the future.

Other Integrations

CC: Tweaked (ComputerCraft) networking cable can be made curvy since 1.15.0.

Known Incompatibilities

Won't work if "Immersive Portals" is installed.
[1.20.1+] Won't launch if some version of the "Physics Mod" is installed.

Additional Info

Most of the mod's functionalities are implemented in Rust compiled to native code, rather than Java.
Supported platforms: Windows (x64), Linux (x64/ARM64), MacOS (x64/ARM64 Apple Silicon)
Additional platforms supported on 1.18.2 and above: Android (x64/ARM64), FreeBSD (x64/ARM64)
32-bit platforms will not be supported.
Pipe types and recipes are customizable for modpack use. See config/curvy_pipes_default.yaml for details.
Feel free to redistribute or use in any modpack.