Opa一站式Web应用开发语言

原文地址：http://www.infoworld.com/d/application-development/introducing-opa-web-dev-language-rule-them-all-172060?page=0,0&source=IFWNLE_jw_2011-09-13

一个全新的语言，注意，并非框架(像Rails，Grails)，有了它，可以不用写js，不用写sql，不用n层的复杂架构，甚至部署也非常容易，因为这个叫Opa的语言，一站式，包含一切Web应用需要的东西。

开源协议：AGPL

优点：简单易学，一站式特性，适用于原型系统，要求不高的企业内部应用
缺点：一门新语言；封闭(view自动生成，持久化自动实现，)定制优化的可行性低；虽然本身开放源代码，但其开发语言是另一门更生僻的“OCaml”，需要扩展Opa你得先学它

In recent weeks, I've been fascinated with Opa, a new language that aims to eliminate all of the convoluted code-wrangling from Web application development. With Opa, you don't use one language to script your UI, another to code your business logic, and so on. Everything, from the client-facing code to the database access, is written in Opa.

Unlike with some rich Internet application (RIA) platforms, users don't need a browser plug-in to use Opa applications. The parts of your Opa code that need to run in the client browser are automatically compiled into JavaScript.

Other parts of your code run on the server, as appropriate. Here, Opa is unusual in that it's a truly all-in-one solution. Unlike most platforms, you don't need to install and maintain a stand-alone Web server, database server, application server, and middleware layer to get going. The Opa platform provides everything, from the Web server to the database server to the client- and server-side frameworks.

As a result, Web applications built with Opa can be incredibly compact. There's very little of the "glue code," boilerplate, and drudge work that characterizes most Web platforms. The sample application is a distributed Web-based chat client that comprises just 27 lines of Opa code. A full description of how to develop and deploy Web applications in Opa would be too long to include here, but I encourage you to browse the copious documentation available online.