I built 36 Mojo libraries and test each one against the reference it imitates, not against itself: mojo-json is byte-identical with Python’s json, mojo-gguf writes the same bytes as llama.cpp’s converters and quantizer, mojo-tokenizers returns the same ids as the Hugging Face tokenizers crate, mojo-cv checks each op against cv2 5.0, mojo-pyformat rounds exactly like Python’s format().
All 36 are conda packages now:
pixi workspace channel add https://conda.modular.com/max https://prefix.dev/amarbaro/amarbaro
pixi add mojo-json
Each package was installed that way into a fresh workspace, and its quickstart built and ran, before I called it published.
They cover the jobs around a program’s core: JSON, msgpack, gzip/zlib, zstd/lz4, SQLite, safetensors, GGUF, tokenizers, an argparse-style CLI, subprocess, inotify, an epoll loop, logging, Prometheus metrics, sd_notify, hashing, semver, glob, property tests, a benchmark harness, and an immediate-mode GUI composed on the GPU. Each repo ships its oracle in tools/, a negative control that must fail, docs/api.md, docs/design.md, and an agent skill in skills/, so a coding agent can use the library without guessing.
Index with versions and CI badges: GitHub - amarbaro/mojo-libs: Index of the amarbaro Mojo libraries: each tested against an oracle, with API docs and an agent skill · GitHub
Keeping 36 repos green across Mojo releases: every library calls one shared workflow, and a weekly matrix builds all of them on stable and on the current nightly, grouping failures by first compiler error into one issue each. The 2026-11-08 nightly (1.3.0.dev2026110805) broke five libraries: UnsafePointer is gone, ord(String) now raises, and every binary now loads libLLVM, whose zlib shadows the system one (mojo-gzip segfaulted until it opened libz with RTLD_DEEPBIND). All 36 pass on 1.2, and 35 on that nightly (xmojo pins 1.2.0).
Apache-2.0, mojo>=1.2.0,<1.3 for most.
If one of them saves you work, a star on GitHub is appreciated, and bug reports are welcome.