Composer (MosaicML)
https://github.com/mosaicml/composer
Open-source training library from MosaicML (Databricks) — Trainer + recipes for fast convergence; underlies the MPT model training stack.
Archived · Verified 2026-10-27 · fresh as of 2026-10-27 · 18 cited facts, 2 with a third-party source · 1 recorded change · Suggest a correction
At a glance
- Type
- PyTorch training library repo fix
- Tier
- T2
- Section
- Training infrastructure
- Latest release
- v0.32.1 (2025-07-26) — mosaicml registry fix
- License
- Apache-2.0 repo fix
- Pricing
- searched not found fix
- Funding
- MosaicML acquired by Databricks for $1.3B in 2023-07; Composer remains Apache-2 OSS. third-party fix
- Freshness
- 2026-10-27 fix
- Layer
- model-infra repo fix
- Licensing
- open-source repo fix
- Developer activity
- OpenRank 0.17 (12-mo avg 7.44) · 2 participants — 2026-09 third-party fix
When to use
Optimised for: searched not found
Anti-fit: searched not found
Pros & cons
Pros
searched not found
Cons
searched not found
Claims & capabilities
MosaicML acquired by Databricks $1.3B (2023).
Technical surface
- API surface
- searched not found
- Backend storage
- searched not found
- Deployment
- Self-hosted only — library
- Embedding model
- not applicable — not a memory product
- Multi-tenancy
- searched not found
- MCP
- searched not found
- A2A
- searched not found
- OpenTelemetry
- searched not found
Similar systems
Other training infrastructure in the catalog, ranked by inbound references.
- MLflow T1
Databricks-incubated open platform for ML lifecycle — tracking, projects, models, model registry. Standard ML-ops baseline. MLflow 3.0 (2024) added LLM-eval features.
- AWS SageMaker T1
AWS's managed ML platform — Studio, Training, HyperPod (large-scale clusters), Endpoints. Industry-standard for enterprise AWS-hosted training.
- Weights & Biases T1
Experiment-tracking and ML-ops platform (metrics, artifacts, sweeps, Weave tracing/evals). Acquired by CoreWeave (completed 2025-05-05, ~$1.7B); now part of CoreWeave Forge.
- Comet ML T2
ML experiment tracking + LLM evaluation platform (Opik for LLM eval). Comet competes head-to-head with Weights & Biases.
- Azure Machine Learning T1
Microsoft Azure's managed ML platform — pipelines, AutoML, Designer, prompt flow (LLM). Heavy integration with Azure OpenAI and Azure AI Studio.
- LoRA T3
Microsoft Research's Low-Rank Adapters method — trains rank-r matrices added to attention weights; 10000x parameter reduction. Foundation of all adapter-style fine-tuning.
Sources (17 cited facts, 2 third-party)
Each fact links to the page it came from; the badge says who published it (how to read sources).
- What it is PyTorch training library repo
- What it does & what's distinct Open-source training library from MosaicML (Databricks) — Trainer + recipes for fast con… repo
- Claims / benefits MosaicML acquired by Databricks $1.3B (2023). repo
- Created 2022 repo
- Latest release v0.32.1 (2025-07-26) — mosaicml registry
- License Apache-2.0 repo
- GitHub mosaicml/composer — ~5.5k stars, archived 2026-10-23, last push 2026-04 repo
- Funding MosaicML acquired by Databricks for $1.3B in 2023-07; Composer remains Apache-2 OSS. third-party
- Deployment Self-hosted only — library registry
- Code/weights release Active — last commit 2026-04 · 5,480★ repo
- commit-trajectory [{"ym":"2023-06","cum":1730},{"ym":"2023-07","cum":1760},{"ym":"2023-08","cum":1816},{"y… repo
- download-trajectory [{"ym":"2025-11","monthly":64883,"cum":64883},{"ym":"2025-12","monthly":49247,"cum":1141… registry
- architecture-deployment-locus local repo
- licensing-bucket open-source repo
- positioning-platform-vs-product platform repo
- taxonomy-three-layer-rollup model-infra repo
- developer-activity-opendigger {"activity":4.03,"as_of":"2026-09","openrank_12mo":7.44,"openrank_current":0.17,"partici… third-party
What changed
Changes to this record's lifecycle, licence, release, pricing and hosting facts, from the catalog's git history. Subscribe (Atom)