The Extended Support Release (ESR) channel of SpiderMonkey continues to be the
recommended stream to embed in your applications. The next ESR will be version
91 which is currently in active developement. The (soft) code freeze for this
release is July 8, 2021, with stable release planned for August 10, 2021. The
current ESR-78 is expected to receive security updates until the end of October.
A few highlights of the upcoming release are:
- Warp JIT simplified the engine, reduces memory and increases performance of complex scripts.
coverage of the ECMAScript conformance suite, test262).
- New parsing and caching APIs are being previewed to support lower overhead performance caching of bytecode and new opportunities to reduce memory when using cached bytecode.
- ArrayBuffer size limit was increased to 4GB and may be increased further in future.
- Many more changes are listed in the blog.
Notable breaking changes:
- The ‘jsapi.h’ header file continues to be split into smaller files and a few new includes may be needed.
- The dev team has migrated away from using
./configurein favour of
mach buildworkflows and documentation is starting to reflect this. The configure
script continues to work but direct usage is being deprecated.
- The Migration Guide is being expanded as we discover API breakage.
There is still time to fix issues and papercuts, so reach out here, matrix, or
Bugzilla if you have local workarounds that might be worth upstreaming.