Ceylon M4 发布了，同时发布的还有 Ceylon IDE M4，这两个版本都要求 Java 7 的支持。预计明年 1 月份发布 Beta 版本。
该版本包含的新特性有：
- member class refinement (type families)
- class and interface aliases
- union and intersection aliases
- new syntax for package and module descriptors
- assertions
- condition lists
- support for calling super-interface implementations of refined members
- maven repositories
- pluggable command-line tools, git-style
- better support for optional types in Java
- JDK/Jigsaw modules
- all-new API doc redesign
- more than 300 features and bug fixes
Ceylon IDE M4 改进内容：
- support for JavaScript compilation and execution,
- module import completion,
- the brand new Ceylon Repository Explorer view,
- support for Maven repositories, and
- more than 30 other improvements and bug fixes.