Kotlin 1.3 RC 版发布了，这是 1.3 的最新预览版和候选版，更新内容主要包含与新语言功能相关的关键错误修复，值得注意的变化包括：

• Ktor is wrapping up its API and looking forward to your feedback. Ktor is a framework for building web applications, HTTP services, mobile and browser applications. It’s elegant, asynchronous and built on coroutines.

• The official code style is now used for all new projects. We also encourage you to migrate old projects to the official style.

• The main entrypoint can now take no parameters and also can be a suspending function.

• Experimental support for scripting introduced in version 1.2.50 has been reworked and improved.

• An experimental kotlinx.serialization plugin has been merged to the main Kotlin project. Now it’s a bundled compiler plugin.

• There are new deprecations in the standard library, as well as errors for some old deprecations.

• Annotations in the org.jetbrains.annotations package were extracted from the standard library to separate artifacts.

此外，Kotlin 1.3 协同程序已达到稳定状态。现在是使用旧的实验协同程序进行迁移库的好时机，官方也提供了工具帮助我们迁移代码。详情请查看发布说明。

新闻来源：Kotlin 1.3 RC 版发布：迁移你的 coroutines 程序吧！