v0.1.13414 Aug 2026·JavaScript & JIT, Memory & reading

WebAssembly now runs real compiled modules, not just toy ones

The WebAssembly engine that landed last release ran hand-written modules. Real modules - anything a Rust, C or C++ toolchain emits - lean on three things it did not yet have: indirect calls through a function table (how compiled code does function pointers, virtual methods and closures), bulk memory operations (the fast memory copy and fill the compiler reaches for constantly), and saturating float-to-integer conversions (LLVM's default, which clamp instead of trapping). This release adds all three, so the engine now runs the kind of WebAssembly the web actually ships. Each is proven against the reference runtime's WebAssembly on a fixture built and run there: a dispatch table that routes to add, subtract or multiply through call_indirect, and a module that fills and copies linear memory and does a saturating truncation, both byte-identical here. Web APIs moves 52 to 54 and overall 53 to 54.

Parity with the reference browser

74overall, as of v0.1.343

Web APIs / DOM surface42

Security architecture66

GPU / graphics acceleration68

DevTools / extensions72

Networking85

Media85

Accessibility85

Real-world site compatibility99

HTML parsing100

CSS parsing + selectors100

Layout: block / flex / grid / tables / writing-modes100

Paint + visual100

JavaScript language100

JavaScript performance (JIT)100

HTML parsing100

What changed 3 changes

JavaScript & JIT	call_indirect + function tables (wasm/decode.rs element section, wasm/exec.rs): the element section fills a function table, and call_indirect pops a table slot, resolves the function, checks its declared type matches the call site, and calls it - the mechanism compiled code uses for function pointers and virtual dispatch.
Memory & reading	The 0xfc opcode family (wasm/exec.rs): saturating truncation i32/i64.trunc_sat_f32/f64_s/u (clamp NaN to 0 and out-of-range to the type bounds, LLVM's default) and bulk memory memory.copy / memory.fill, all bounds-checked. These are emitted by ordinary Rust/C++ builds, so their absence alone failed most real modules.
Memory & reading	Proven against the reference JavaScript runtime: a call_indirect dispatch table (dispatch(0,7,3)=10, (1,7,3)=4, (2,7,3)=21) and a bulk-memory + trunc_sat module both decode and run byte-identically to the reference runtime's WebAssembly. Whole conformance suite unchanged.