* **fs**: corruption can be caused by `fs.writeFileSync()` and append-mode `fs.writeFile()` and `fs.writeFileSync()` under certain circumstances, reported in [#1058](https://github.com/iojs/io.js/issues/1058), fixed in [#1063](https://github.com/iojs/io.js/pull/1063) (Olov Lassus).
* **iojs**: an "internal modules" API has been introduced to allow core code to share JavaScript modules internally only without having to expose them as a public API, this feature is for core-only [#848](https://github.com/iojs/io.js/pull/848) (Vladimir Kurchatkin).
* **timers**: two minor problems with timers have been fixed:
- - `Timer.close()` is now properly idempotent [#1288](https://github.com/iojs/io.js/issues/1288) (Petka Antonov).
+ - `Timer#close()` is now properly idempotent [#1288](https://github.com/iojs/io.js/issues/1288) (Petka Antonov).
- `setTimeout()` will only run the callback once now after an `unref()` during the callback [#1231](https://github.com/iojs/io.js/pull/1231) (Roman Reiss).
- NOTE: there are still other unresolved concerns with the timers code, such as [#1152](https://github.com/iojs/io.js/pull/1152).
* **Windows**: a "delay-load hook" has been added for compiled add-ons on Windows that should alleviate some of the problems that Windows users may be experiencing with add-ons in io.js [#1251](https://github.com/iojs/io.js/pull/1251) (Bert Belder).