Stackless Python, or Stackless, is a discontinued Python programming language interpreter. Its GitHub repository has been archived since February 2025, and the project has been officially discontinued.
It was so named because it avoids depending on the C call stack for its own stack. In practice, Stackless Python uses the C stack, but the stack is cleared between function calls. The most prominent feature of Stackless is microthreads, which avoid much of the overhead associated with usual operating system threads. In addition to Python features, Stackless also adds support for coroutines, communication channels, and task serialization.
The MMORPG game EVE Online is one of the major users of Stackless Python, since 2003 (with Python 2.1, then 2.3, 2.5, 2.7), and the company behind it Fenris Creations (previously CCP Games) one of the main contributor to it, but started to move away from it, i.e. started migration to Python 3 in 2026 (in the meantime they open sourced the game engine, and one part is a component "designed to match that of Stackless Python as closely as possible" though it diverges also).
What is Stackless Python?
Stackless Python by The Stackless Team is open-source Windows software in the ides & code editors category. It is written in Python and C. Besides Windows, it is available for Linux.
Installation and requirements
The publisher provides EXE installers for 64-bit and 32-bit Windows. It can be installed for the current user only, without administrator rights. It needs Windows 10 or newer. A silent install is possible with the installer’s documented switches.
Updates and version history
The current version is 3.7.9150.0, released on August 15, 2021. The version history goes back to March 30, 2021: 13 releases, all linked to the official files. The last update is more than a year old. The source repository has been archived, so further updates are unlikely.
Popularity and file types
The source code on GitHub (stackless-dev/stackless) has 1,050 stars. Wikipedia has an article about it in 12 of our languages. On Windows it registers 1 file type, including .py. Similar programs include OpenCode, RStudio and Node.js (LTS).
Project description on GitHub: “The Stackless Python programming language”
Pros / Cons
Pros
- Open source: the code can be inspected and built by anyone
- Documented silent install
- Installs without administrator rights
- Also runs on Linux
Cons
- No native ARM64 build
- No update for more than a year
- Source repository archived
In short: Stackless Python is an open-source ides & code editor tool for 64-bit and 32-bit PCs. Updates have slowed down. Administrators can deploy it unattended.
Is Stackless Python safe to download?
- The file is served by stackless.com; check that it is the publisher’s official mirror
- The download link does not use HTTPS
- A SHA256 hash is published, so you can verify the file:
025B7CFF9AB5B2DB78521319D23CA6B30E69CD4675E61E242A59C937E4015B27· Open the VirusTotal report for this hash - The link answered when we last checked it (October 22, 2026)
- The source code is public
- ExeAtlas does not host, wrap or modify installers
Related guide: How to check a file’s SHA256 hash on Windows
Recent versions
All 13 versions ›| Version | Date | Size | Files |
|---|---|---|---|
| 3.7.9150.0Latest | August 15, 2021 | — | 64-bit EXE32-bit EXE |
| 3.7.5 | March 30, 2021 | — | 64-bit EXE |
| 3.7.4 | March 30, 2021 | — | 64-bit EXE |
| 3.7.3 | March 30, 2021 | — | 64-bit EXE |
| 3.7.2 | March 30, 2021 | — | 64-bit EXE |
| 3.6.8 | March 30, 2021 | — | 64-bit EXE |
| 3.6.6 | March 30, 2021 | — | 64-bit EXE |
| 3.6.4 | March 30, 2021 | — | 64-bit EXE |
Install from the command line
Silent install ›winget install --id stackless.stackless -estackless-3.7.9-amd64.exe /quietProgram files (.exe): py.exe
Related guide: How to use winget: install and update apps
Information
- Publisher
- The Stackless Team
- Category
- IDEs & code editors
- Licence
- PSF-2.0
- Price
- Free
- Source code
- github.com/stackless-dev/stackless
- Written in
- Python and C
- Requires
- Windows 11 / 10 (Windows 10+)
- Architecture
- 64-bit, 32-bit
- Installer
- EXE
- Other platforms
- Linux
- Version
- 3.7.9150.0
- Released
- August 15, 2021
- Added to the catalogue
- March 30, 2021
- Versions listed
- 13
- GitHub stars
- 1,050
- GitHub forks
- 64
- Website
- github.com
- winget ID
- stackless.stackless
File types it opens (1)
Ratings and reviews
No reviews yet. Be the first to rate it.
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Frequently asked questions
Is Stackless Python free?
Yes. Stackless Python is open-source software under the PSF-2.0 licence.
Is Stackless Python safe to download?
The download comes from stackless.com; ExeAtlas does not host or change the file. Compare its SHA256 hash with the one shown here, or open the VirusTotal report for that hash.
How do I install Stackless Python with winget?
Open PowerShell or Windows Terminal and run the winget command shown on this page. winget downloads the official installer and checks its SHA256 hash before running it.
Can Stackless Python be installed silently?
Yes. The silent install page lists the exact command for each installer.
Which Windows versions does Stackless Python support?
The installer requires Windows 10 or newer and is available for 64-bit and 32-bit.
Does Stackless Python run on ARM (Windows on Arm)?
There is no ARM64 build; Windows 11 on Arm can run the 64-bit and 32-bit version through emulation.
Where can I download an older version of Stackless Python?
The versions page lists all 13 versions with links to their official installer files, back to March 30, 2021.
Can I use Stackless Python without administrator rights?
Yes, there is a per-user installer that does not need administrator rights.
What are alternatives to Stackless Python?
OpenCode, RStudio, Node.js (LTS), Apache NetBeans and Haxe. The alternatives page compares them.
