刚刚引起我们注意的是 MySQL 的手册已经修改了授权许可证，这是从 MySQL 5.5.30 到 5.5.31 时做的改动，该改动影响源码包中的 man 文件夹里的所有页面。

老的手册遵循 GPLv2 许可证(MySQL 5.5.30 或者更早版本)：

This documentation is free software; you can redistribute it and/or modify it only under the terms of the GNU General Public License as published by the Free Software Foundation; version 2 of the License.

而新的手册页面(MySQL 5.5.31 或者更新版本)则采用如下授权协议：

This software and related documentation are provided under a license agreement containing restrictions on use and disclosure and are protected by intellectual property laws. Except as expressly permitted in your license agreement or allowed by law, you may not use, copy, reproduce, translate, broadcast, modify, license, transmit, distribute, exhibit, perform, publish, or display any part, in any form, or by any means. Reverse engineering, disassembly, or decompilation of this software, unless required by law for interoperability, is prohibited.

此举明显的显示出 Oracle 非常不友善的行为。新的许可证跟 GPL 差别巨大，并且明确表达不再使用 GPL 许可证。下图是使用 resolveip 工具获取的两个不同的手册页面的版本说明：包括 man page in 5.5.30 和 man page in 5.5.31.

原文：http://blog.mariadb.org/mysql-man-pages-silently-relicensed-away-from-gpl/

译文：http://www.oschina.net/news/41540/mysql-man-pages-silently-relicensed-away-from-gpl