Additional Implementations and Research Systems
Notable systems adjacent to (or directly implementing) algebraic effects beyond the primary language pages in this folder.
Last reviewed: February 16, 2026.
Effekt
Effekt is a research language centered on effect handlers and direct-style programming.
- Focus: language-level support for handlers and effect polymorphism
- Value: good reference point for modern handler-oriented language design
- Relationship: Similar design goals to Eff and Koka
Reference: Effekt website
Links
Links is a research language for web programming with row-polymorphic effect typing and long-running work on effect handlers.
- Focus: typed effects in client/server/database integrated programming
- Value: shows effect systems in a full-stack language setting
Reference: Links language site
Koka (for context)
Koka is covered in detail in its dedicated page, but it is worth reiterating here as one of the strongest end-to-end designs:
- row-polymorphic effect types with inference
- practical compilation strategies
- active releases in the v3 line
References:
Systems-Language Direction: C + Coroutines
Recent work demonstrates effect handlers implemented in C via coroutine machinery.
- Focus: low-level implementation route without requiring a full new language runtime
- Value: broadens the portability story for handlers
Reference: Effect Handlers for C via Coroutines (ICFP 2024)
WebAssembly Target Direction
Wasm continuation proposals and WasmFX work position WebAssembly as a common low-level target for effect handlers.
- Focus: typed control transfer primitives for compiled handlers
- Value: potential cross-language backend convergence
References:
- Continuing WebAssembly with Effect Handlers (OOPSLA 2023)
- WebAssembly stack-switching proposal repository
Related Topics
- For systems-language implementations with virtual threads, see Java Loom and Scala Ox
- For capability-based effect tracking, see Scala 3 Capabilities and Bluefin
- For the main WebAssembly effect handler proposal, see WasmFX
Notes
- This page intentionally excludes systems that are only loosely "effect-like" (for example, generic safety/ownership claims without handler semantics).
- For full historical context, see Evolution of Effect Systems; for active research, see Key Papers.