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.
主页：http://ceylon-lang.org/
下载：http://ceylon-lang.org/download/
来自:开源中国社区
