Python 3.14.0 (www.python.org)

Python 3.14.0 (stable, Oct 7, 2025) introduces a suite of runtime, tooling and build changes aimed at better performance, concurrency and observability. Highlights include official support for Free‑threaded Python (PEP 779) and Multiple Interpreters in the standard library (PEP 734), which together enable safer, higher‑throughput concurrency patterns for CPU‑bound workloads and co‑hosting of isolated runtimes—important for parallel model training, inference servers, and embedding multiple models in one process. An experimental JIT is shipped in official macOS and Windows binaries, and a new opt‑in interpreter variant for recent compilers promises notable performance wins when built from source. Deferred evaluation of annotations (PEP 649) reduces runtime overhead for heavy type/metadata usage typical in ML codebases. 3.14 also adds practical tooling and library updates: Template string literals (PEP 750), a stdlib compression.zstd module (PEP 784) for Zstandard‑compressed datasets, a zero‑overhead external debugger interface (PEP 768), better remote pdb attach support, and a formally verified HMAC implementation from HACL*. Build and distribution changes include official Android binaries, Sigstore replacing PGP signatures for artifact verification (PEP 761), and a new Windows install manager. Together these changes improve performance, security, and operational tooling for AI/ML engineers while keeping many features opt‑in as they mature.