He almost gave up, if it wasn't for Uber's sponsoring the project.
https://twitter.com/rui314/status/1593464571586830336
See Licensing on https://github.com/rui314/mold/releases/tag/v1.7.0
In Mold linker: targeting macOS/iOS now requires a commercial licenserui314
mold
Rust2020–2026
rui314 / mold
mold
mold 🦠: A Modern Linker in Rust 🦀
80Distinct people
95Mentions
0Explicit recommenders
17.7KGitHub stars
What to know before exploring
What it is
mold 🦠: A Modern Linker in Rust 🦀
GitHub
Where it is used
No documented product use was verified in the last source check.
What people are saying
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Also in these discussions
- mozilla/sccache · linked in 2 of the same discussions
Mentioned in the same Hacker News threads. That is not proof they are substitutes.
This week on Hacker News
Nov 8–Nov 15 UTC · Direct repository links and separately labeled related project stories. Indexed through 11/15/2026, 10:49:33 PM UTC.
No direct repository links were found in the indexed HN discussions over the past seven days. Older discussions are available below.
Mentions over time
HN mentions by year95 dated mentions
Observed mentions: 2020-12-13 19:21:00 UTC to 2026-10-05 20:22:21 UTC.
* An incomplete calendar period is marked with an outlined bar. Its count is not directly comparable with a full period.
Counts come from the repository’s dated source evidence. Index cutoff: 2026-11-02 08:16:59 UTC.
View mention counts and date ranges
| Period | Start (UTC) | End (exclusive, UTC) | Mentions | Submissions | Comments |
|---|---|---|---|---|---|
| 2020 | 2020-01-01 00:00:00 UTC | 2021-01-01 00:00:00 UTC | 2 | 1 | 1 |
| 2021 | 2021-01-01 00:00:00 UTC | 2022-01-01 00:00:00 UTC | 15 | 7 | 8 |
| 2022 | 2022-01-01 00:00:00 UTC | 2023-01-01 00:00:00 UTC | 34 | 8 | 26 |
| 2023 | 2023-01-01 00:00:00 UTC | 2024-01-01 00:00:00 UTC | 20 | 4 | 16 |
| 2024 | 2024-01-01 00:00:00 UTC | 2025-01-01 00:00:00 UTC | 9 | 5 | 4 |
| 2025 | 2025-01-01 00:00:00 UTC | 2026-01-01 00:00:00 UTC | 8 | 1 | 7 |
| 2026 (partial) | 2026-01-01 00:00:00 UTC | 2027-01-01 00:00:00 UTC | 7 | 2 | 5 |
From the project README
An excerpt from the repository, fetched Nov 13, 2026.
Read the project’s introduction
mold: A Modern Linker
mold is a high-performance drop-in replacement for existing Unix linkers,
designed to speed up builds. In our August 2026 benchmarks, it links 4.9x
faster than LLVM lld and 1.9x faster than
wild at the median; see
Benchmark for the full results.
mold is written by the original developer of LLVM lld, the linker that
Android, Chrome, FreeBSD, PlayStation, Nintendo Switch, and other production
systems are built with. mold started as an effort to build an even faster
linker from scratch, free of the architectural limits its author had run into
while optimizing lld. It has been in production use since 2021, and today it
is the default linker of many large open-source projects and is used
internally by many companies.
mold supports x86-64, i386, ARM 32/64, RISC-V 32/64, PowerPC 32/64, s390x,
LoongArch 32/64, SPARC64, m68k, and SH-4.
Why does linking speed matter?
If you are using a compiled language such as C, C++, or Rust, a build consists
of two phases. In the first phase, a compiler compiles source files into
object files (.o files). In the second phase, a linker takes all object
files and combines them into a single executable or shared library file.
The second phase can be time-consuming if your build output is large. mold can
speed up this process, saving you time and preventing distractions while
waiting for a lengthy build to finish. The difference is most noticeable
during rapid debug-edit-rebuild cycles.
Benchmark
Here is a performance comparison of lld, wild, and mold when linking nine
large programs on two machines:
AMD Ryzen Threadripper 7980X (64 cores) running Ubuntu 24.04
Apple M1 Ultra (16 performance cores and 4 efficiency cores) running Fedora
Asahi Remix 42; the benchmark is restricted to the performance cores
The Threadripper represents many-core workstation and server processors, and
the M1 Ultra represents high-performance desktop processors.
All three linkers were built from source in release configuration as of
2026-08-28 and ran with their default options. Times are wall-clock times as
seen by the caller, the median of three runs after a warm-up. The ARM64 rows
are the ARM64 builds of the same programs. The benchmark suite, including all
linker inputs, is available on Zenodo.
AMD Ryzen Threadripper 7980X, debug builds
Program (output size)
lld
wild
mold
wild/mold
lld/mold
Blender 5.2 (2.46 GiB)
4.72s
1.98s
0.86s
2.3x
5.5x
Chromium 145 (4.51 GiB)
16.64s
3.98s
1.65s
2.4x
10.1x
Chromium 145 ARM64 (4.76 GiB)
20.91s
N/A
1.83s
N/A
11.4x
Clang 21 (4.19 GiB)
6.19s
3.71s
1.34s
2.8x
4.6x
ClickHouse 26.1 (5.58 GiB)
6.62s
4.40s
0.98s
4.5x
6.7x
Firefox 149 (2.37 GiB)
5.11s
N/A
0.78s
N/A
6.5x
Firefox 149 ARM64 (2.43 GiB)
6.40s
N/A
0.93s
N/A
6.9x
Godot 4.6 (1.01 GiB)
1.77s
1.08s
0.46s
2.3x
3.8x
LibreOffice 26.2 (0.98 GiB)
3.46s
1.41s
0.44s
3.2x
7.9x
PyTorch 2.9 (3.51 GiB)
4.35s
2.48s
0.80s
3.1x
5.4x
TensorFlow 2.21 (9.55 GiB)
50.73s
N/A
3.15s
N/A
16.1x
AMD Ryzen Threadripper 7980X, release builds
Program (output size)
lld
wild
mold
wild/mold
lld/mold
Blender 5.2 (0.24 GiB)
0.85s
0.30s
0.20s
1.5x
4.2x
Chromium 145 (0.58 GiB)
6.48s
N/A
0.64s
N/A
10.2x
Chromium 145 ARM64 (0.60 GiB)
7.91s
N/A
0.73s
N/A
10.8x
Clang 21 (0.21 GiB)
0.53s
0.23s
0.11s
2.2x
5.0x
ClickHouse 26.1 (1.23 GiB)
3.18s
2.07s
0.41s
5.0x
7.7x
Firefox 149 (0.22 GiB)
1.01s
0.41s
0.21s
2.0x
4.9x
Godot 4.6 (0.15 GiB)
0.44s
0.21s
0.08s
2.7x
5.8x
LibreOffice 26.2 (0.19 GiB)
1.13s
0.57s
0.19s
3.0x
6.0x
PyTorch 2.9 (0.31 GiB)
0.68s
0.32s
0.15s
2.2x
4.7x
TensorFlow 2.21 (0.73 GiB)
9.62s
N/A
0.70s
N/A
13.7x
Apple M1 Ultra, debug builds
Program (output size)
lld
wild
mold
wild/mold
lld/mold
Blender 5.2 (2.46 GiB)
3.21s
1.81s
1.56s
1.2x
2.1x
Chromium 145 (4.51 GiB)
9.54s
3.49s
2.22s
1.6x
4.3x
Chromium 145 ARM64 (4.76 GiB)
12.67s
N/A
2.31s
N/A
5.5x
Clang 21 (4.19 GiB)
4.40s
2.78s
2.96s
0.9x
1.5x
ClickHouse 26.1 (5.58 GiB)
4.92s
3.50s
1.71s
2.1x
2.9x
Firefox 149 (2.37 GiB)
3.21s
N/A
1.12s
N/A
2.9x
Firefox 149 ARM64 (2.43 GiB)
4.13s
N/A
1.12s
N/A
3.7x
Godot 4.6 (1.01 GiB)
1.12s
0.81s
0.62s
1.3x
1.8x
LibreOffice 26.2 (0.98 GiB)
2.08s
0.94s
0.63s
1.5x
3.3x
PyTorch 2.9 (3.51 GiB)
3.07s
2.10s
1.45s
1.4x
2.1x
TensorFlow 2.21 (9.55 GiB)
43.68s
N/A
4.43s
N/A
9.9x
Apple M1 Ultra, release builds
Program (output size)
lld
wild
mold
wild/mold
lld/mold
Blender 5.2 (0.24 GiB)
0.56s
0.20s
0.25s
0.8x
2.3x
Chromium 145 (0.58 GiB)
4.25s
N/A
0.78s
N/A
5.5x
Chromium 145 ARM64 (0.60 GiB)
5.17s
N/A
0.91s
N/A
5.7x
Clang 21 (0.21 GiB)
0.30s
0.15s
0.14s
1.0x
2.1x
ClickHouse 26.1 (1.23 GiB)
1.94s
0.95s
0.55s
1.7x
3.5x
Firefox 149 (0.22 GiB)
0.56s
0.23s
0.20s
1.1x
2.7x
Godot 4.6 (0.15 GiB)
0.26s
0.11s
0.11s
1.0x
2.3x
LibreOffice 26.2 (0.19 GiB)
0.62s
0.30s
0.23s
1.3x
2.7x
PyTorch 2.9 (0.31 GiB)
0.43s
0.22s
0.17s
1.3x
2.5x
TensorFlow 2.21 (0.73 GiB)
8.07s
N/A
0.68s
N/A
11.9x
N/A indicates that the linker cannot link that program. wild's Chromium
release links are also marked N/A because wild does not implement --icf=all
and links without identical code folding.
Why is mold so fast?
mold owes its speed to pervasive parallelism and to efficient data structures
and algorithms. For details, read our paper "mold: A Massively Parallel
Linker" (ASPLOS 2027), available at https://arxiv.org/abs/2608.23228.
Installation
Binary packages for the following systems are currently available:
Prebuilt binaries for Linux on x86-64, ARM64, ARM32, RISC-V, PPC64LE, s390x,
and LoongArch are also attached to each
GitHub release.
How to Build
mold is written in Rust and built with Cargo. It requires Rust 1.95 or later;
if your system's Rust is older, install the stable toolchain with
rustup. You also need Git and a C compiler such as GCC or
Clang, which you can install with your system's package manager.
Compile mold
git clone https://github.com/rui314/mold.git
cd mold
cargo build --release
The executable is target/release/mold.
Install mold
Run
Read the full README on GitHubWhat Hacker News says
34 sourcesor the core ideas from mold [1] make their way to gold and other linkers.
[1] https://github.com/rui314/mold/blob/main/docs/design.md
In Mold linker: targeting macOS/iOS now requires a commercial licenseMold linker: targeting macOS/iOS now requires a commercial license
145 points · Open discussionTL;DR from https://github.com/rui314/mold/releases/tag/v1.7.0
>I'd like to inform users that I'm seriously considering changing the mold's license from AGPL to a source-available license unless I secure big funding. The new license would be something like individuals can use it for free but corporate users have to pay. mold started as my personal project, and I've been working on this full time for two years so far. I thought that I could earn a comfortable income if mold become popular, but unfortunately, I'm still losing my money. I think I need to take an action to make the project sustainable long term.
In Problem with my open-source startupMold linker may switch to a source-available license
205 points · Open discussionRui, can you open a new Discussions thread at https://github.com/rui314/mold so we can transfer the whole conversation there?
We could ask for advice from other project developers that have succeeded on their own journey.
In Chibicc – A Small C CompilerSimple approach:
Set up a page saying that support costs a quarter hour of engineering average salary for the country/year/employee who uses Mold. Eg. in a company in the USA, with 30 in the engineering department, that would be $600/yr. Let them know that the license continues to be valid if the company grows during the year.
When a company pays for a license, you give them a license code like "2023-06-Vmware-7676". Tell them to put that code into ~/.mold/license, or to set the env var MOLDLICENSE= to that. The same code lets them into a discussion forum.
When the linker starts, it prints a string saying "Mold Linker, Licensed to Vmware. Support license expires June 2023. See https://github.com/rui314/mold/wiki/support for details".
If there is no license, or the license is expired, it prints "This program is UNSUPPORTED by @
Read the rest
rui314. For a paid supported version, see https://github.com/rui314/mold/wiki/support".
But obviously it still works just fine, license or no license.
https://github.com/rui314/mold don't support live update, but fast enough to boost productivity.
In Bringing a dynamic environment to C: My linker projectMold 1.4.1 – macOS now available as an alpha feature
2 points · Open discussionI have to say, and pardon me for saying so, but Carbon seems to be utterly uninteresting to me. They are not solving any interesting problems that shows me that they are creating a modern language.
As an example, look at this issue from the mold linker: https://github.com/rui314/mold/issues/584
They are looking at creating an embeddable custom dynamic linker in order to greatly reduce loading times, by fixing locations as the file gets loaded in.
The equivalent in Carbon would (for example) be to create a new type of exception handling that changes how we think about exceptions, performance and their cost. Perhaps something like the static exceptions that Herb Sutter has been working on. Instead, they are not adding exceptions at all.
You will have to excuse my disappointment.
In Carbon’s most exciting feature is its calling conventionAh, I overlooked this explanation at first: https://github.com/rui314/mold/blob/main/docs/design.md
Thanks for the great write up as well as mold itself!
In Mold/macOS is 11 times faster than the Apple's default linker to link ChromeI can infer from context that mold is a linker. It took searching for https://github.com/rui314/mold to learn what it actually was, though:
"mold is a faster drop-in replacement for existing Unix linkers. It is several times faster than the LLVM lld linker, the second-fastest open-source linker which I originally created a few years ago. mold is designed to increase developer productivity by reducing build time, especially in rapid debug-edit-rebuild cycles."
I don't understand how things like this still manage to front-page without a cursory explanation.
In Mold/macOS is 11 times faster than the Apple's default linker to link ChromeIt's being discussed (https://github.com/rui314/mold/issues/117) but haven't reached any conclusion. The problem is that the jobserver protocol assumes that one process is one job, and its model doesn't fit very well to programs such as mold.
In Mold/macOS is 11 times faster than the Apple's default linker to link ChromeShowing the 15 most recent of 34 sources. Enable JavaScript to search and browse every indexed mention.