根据Grails 1.2的README：
Grails is a web application framework based on the Groovy language that endorses the DRY (don't repeat yourself) and coding-by-convention philosophies. Grails runs on the Java Virtual Machine and thus has access to the entire Java Platform.
With Grails you can easily create web applications thanks to:
- a complete development and deployment environment. All dependencies and configuration that is required to the run Grails applications in a web server are provided by Grails. The only thing you have to worry about is your application code.
- inclusion of an embedded web server
- development mode that automatically reloads changes made to application code, without having to restart the web server.
- automatic persistence mapping of domain classes with automatic relationship management.
- scaffolding on data access classes for rapid development of CRUD (Create, Read, Update, Delete) operations.
- powerful view technology with dynamic tag libraries and support for Groovy Server Pages (GSP)
初步试用了Grails，随记如下：
1. 安装比较简单方便，（当然比rails稍稍复杂，这个主要归功于gem的包管理)，上手也算比较快。
2. generator等命令的使用上没有rails的自然，需要一些时间适应，另外一个就是感觉每个命令执行都有点慢，可能要研究一下Grails是怎么运作的。
3. domain-class完全是无侵入的POJO，这个是非常的不错。
4. 默认已经包含了59个依赖库(Grails 1.2已经全面采用Spring 3.0了)，配置方面还是稍嫌复杂，不过和一般的Java WEB项目比起来，还是简洁不少。
5. groovy语言语法不太习惯，相反ruby倒是比较容易适应。
6. 数据的持久化方面，新手可能会有些疑惑，还没搞明白怎么重启应用而保留数据。
7. 目录结构方面似乎不够Rails的清爽。
管中窥豹，这些就是Grails的初体验，之后再找时间更深入的了解一下Grails，毕竟是SpringSource在大力推动的，而且现在JVM上的脚本语言应该还是比较有意思的。
