# Doc

The reference docs.

* [SRS 4.0 English](https://ossrs.io/lts/en-us/docs/v4/tools/specs)
* [SRS 4.0 中文文档](https://ossrs.net/lts/zh-cn/docs/v4/tools/specs)

* [SRS 5.0 English](https://ossrs.io/lts/en-us/docs/v5/tools/specs)
* [SRS 5.0 中文文档](https://ossrs.net/lts/zh-cn/docs/v5/tools/specs)

Winlin