Extism Reviews in 2026

Audience

Developers searching for a free solution to write plug-ins for apps of all types and sizes

About Extism

Extism is an open-source, universal plug-in system to make all software programmable, and it's powered by WebAssembly. In-depth documentation, constantly updated as the project grows. 15+ officially supported Host SDKs, making Extism embeddable in the most popular languages. 7+ officially supported PDKs, to write plug-ins in whichever language a developer would like. A growing set of runtime features makes Extism an excellent plug-in system for apps of all types & sizes. Fully-featured canonical reference demo with Elixir host SDK, and plugins in Rust, TypeScript, & Javascript. Implementation of a turn-based multiplayer game platform and games included to play and review. Games are implemented as WebAssembly modules containing a specific set of exports. Check out the source code on GitHub, download the installer, and get started. 100% open-source code. Fork it, experiment, & run your own game server.

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WebAssembly

WebAssembly (abbreviated Wasm) is a binary instruction format for a stack-based virtual machine. Wasm is designed as a portable compilation target for programming languages, enabling deployment on the web for client and server applications. The Wasm stack machine is designed to be encoded in a size- and load-time-efficient binary format. WebAssembly aims to execute at native speed by taking advantage of common hardware capabilities available on a wide range of platforms. WebAssembly describes a memory-safe, sandboxed execution environment that may even be implemented inside existing JavaScript virtual machines. When embedded in the web, WebAssembly will enforce the same-origin and permissions security policies of the browser. WebAssembly is designed to be pretty-printed in a textual format for debugging, testing, experimenting, optimizing, learning, teaching, and writing programs by hand. The textual format will be used when viewing the source of Wasm modules on the web.

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Pricing

Starting Price:

Free

Free Version:

Free Version available.

Integrations

API:

Yes, Extism offers API access

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Ratings/Reviews

Overall 0.0 / 5

ease 0.0 / 5

features 0.0 / 5

design 0.0 / 5

support 0.0 / 5

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Product Details

Platforms Supported

Mac

Linux

Training

Documentation

Support

Online

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